This is a chronicle about Christmases past: a strange tale of some strange tapes. It is about the television festivities from the latter part of the last century that were never meant to be televised, and were only meant to be seen by those behind the scenes.

The tapes in question were the work of the technicians whose responsibility was normally to make what reached the screen seem as slick and seamless as possible, but who now gleefully turned the tapestry around and revealed all of the comical messiness lurking on the other side. Basically a 'for one night only' insight into the competent being clumsy, the smooth being ruffled, the supposedly nice being really nasty and the sober being a bit silly, they were TV's ultimate office party gift, with copies being handed out each Christmas in take-home bags along with a clingfilm-wrapped slice of cake.

Far from emerging from out of nowhere, they were actually connected to a long and well-trodden international broadcasting tradition. Over in America, Hollywood studios had been showing 'gag reels' of outtakes from their movies (as part of the private entertainment at wrap parties) since at least the early 1930s, and the tradition had then been continued on US TV by many of its bigger budgeted productions (ranging from The Phil Silvers Show to Star Trek).

Its evolution was a little different in the UK, where for a long time the concern about the cost of 'wasted' tape saw entire series, as well as their outtakes, wiped and reused rather than stored and preserved. There was also more of a tendency, at least for a while, to regard any mistakes recorded on tape as evidence of unprofessional behaviour rather than harmless and often humorous signs of simple human fallibility.

This all began to change during the second half of the Seventies. One of the contributing factors was the medium's recent discovery that its waste products actually contained some commercial appeal.

The popularity of ITV's It'll Be Alright On The Night (which began in 1977), alongside the producer/director Harold Snoad's regular 'Comedy of Errors' outtakes feature in the BBC's The Dick Emery Show, meant that British programme-makers underwent a gradual inversion of attitude when it came to their treatment of taped mistakes. No longer regarding them much like barbers do the tufts of hair that have fallen to their floor, they started treating them (albeit very tentatively at first) as potential material for the 'bloopers' market, collecting and classifying them for subsequent sales.

This process also provided the practical basis for putting together 'private' compilations for in-house entertainment. There were so many new technological tricks that were now increasingly available to video editors that the temptation to do something creative with cock-ups had never been keener for those looking to amuse their colleagues at Christmas.

The tradition in television of the festive VT entertainment tape first took root in the editing suites at the BBC. There were a number of probable reasons for it originating there, ranging from the sheer amount of raw material stored in one large building to the size of the in-house audience, and it certainly had an instant impact.

The first one that was widely circulated came in December 1978. Entitled White Powder Christmas (a reference not only to cocaine, of course, but also to the oxide flakes shed by 2in quadruplex videotape as it runs through the machine), it was the brainchild of a talented and mischievous young VT employee called Grant Watkins. Not only a clever and imaginative editor (he would later be described admiringly by a colleague as 'a producer who was masquerading as an engineer'), Watkins was also bold enough, and charming enough, to inveigle his way on to the studio floor and persuade everyone involved to let him or his colleagues film special inserts for these festive projects.

The original forty-three-minute-long video was thus introduced in a disarmingly playful mood by the newsreader Kenneth Kendall (resplendent in a seasonal sweater), and featured some other special contributions from Michael Crawford (in the guise of Frank Spencer), weatherman Jack Scott, presenter Frank Bough, the actor Leonard Rossiter ('I thought that Manual Equalisers was a Spanish waiter until I discovered VT') and the dance troupe Legs & Co, as well as outtakes from such shows as Swap Shop, Dr Who, Q, Blake's 7, Mike Yarwood In Persons, The Dick Emery Show, The Two Ronnies, Rosie, The Goodies, The Generation Game and Play School, along with Esther Rantzen rehearsing in her rollers, a young Prince Charles doing a Goons impersonation, a middle-aged Michael Parkinson getting very tetchy, some memorably awful dance routines, and several festive messages of gratitude from prominent BBC stars.

Very much a blokes' tape for a blokes' era, it also boasted numerous shots of bare breasts and bouncing bottoms, and was padded-out with a surprisingly high number of 'saucy' clips pinched from US TV shows and movies (most notably The Kentucky Fried Movie), but, as a cathartic and playful exercise, it proved a huge morale-boosting hit with many of those who had laboured away in the dark and musty booths during a busy past year of broadcasting.

Emboldened by such a positive reaction, Watkins and the rest of the BBC's VT team moved ahead in a more methodical fashion, carefully logging possible clips for the following Christmas tape as the weeks and months went by. The 1979 effort, called Good King Memorex, thus provided the next staff party with an even bigger and better batch of festive TV trimmings: amusing errors, one or two endearingly amateurish skits, some choreographed songs and dances, the inevitable 'cheeky' female nudity and the odd bit of satisfying score-settling.

Much slicker and better structured than its predecessor, it featured, among other things, a singing weatherman, an incompetent golfer, an incontinent elephant, a randy dalek, a sweary Sue Lawley and, once again, a very, very tetchy Michael Parkinson. John Cleese, Tom Baker, Noel Edmonds, Andrew Sachs, Michael Aspel, Michael Palin and Kenny Everett were some of those familiar BBC figures who contributed their own comic performances to the proceedings, there were several irreverent cartoons of the BBC's top executives, playful party clips from reception, the canteen and the club bar, and there were even a couple of disarmingly cheerful seasonal greetings from the former Prime Ministers Harold Wilson and Edward Heath.

There would be plenty more of much the same over the course of the next few years, but also, every now and then, the party audience might be taken on an excursion into something more adventurous, with a (semi)proper storyline and several attempts at acting. One year, for example, would see a murder mystery spoof in which a hardboiled private detective called Dick Scanner strove to solve a spate of murders within TV Centre of the BBC's most prominent stars and bosses; another tape took the form of a parody of an Arena arts documentary; and a third was styled like an old in-house enculturation aid.

Highlights would include Michael Aspel being bamboozled by a jargon-spouting VT engineer ('This crystal-controlled binary time base corrector, by which a microprocessor controls the actual transport machinery, is the most reliable but expensive and sophisticated machinery in the technological world!') while a nearby nosy dalek looks on before dismissing it all as 'bollocks'; then there was Ian McCaskill's weather forecast for an imminent nuclear war; an hypnotically agonising dance routine, set to the gospel song In My Father's House, in which the sole male performer alternates various rash demonstrations of sexual technique with a valiant battle against a fast-worsening hamstring strain; the famously lugubrious newsreader Peter Woods, clinging on to an Orthodox cross while giving a sardonic tour of the editing suites ('Fancy working in a place called "VT24"! All your life, no sunshine, no one to talk to...no wonder they're so pallid and wan - or even two!'); some well-deserved mockery of the obsession with expensive idents via a few scrunched-up Maltesers packets, a deflating condom and a panoply of cat poop; suitably bitter adaptations of the Madness song House of Fun and the Oasis number Wonderwall that reflected a rapid rise in worker unrest ('I don't believe that anybody really gives a shit about you now'); and a nicely biting satire about the policy of Producer Choice and all of the fall-out from John Birt's much-despised internal market (taking up all of the 1993 tape).

Lowlights would include the early obsession with whatever dance troupe Top of the Pops happened to have available (especially the routine which saw the editor Terry Bettles, clad only in t-shirt, shorts and a Christmas cracker paper hat, being fondled by several young women); a wince-inducing Bruce Springsteen parody called Bored in the BBC, which looked and sounded like some bizarre hostage punishment stunt; a weirdly random Highway Code routine, and a similarly awful and unoriginal 'bad TV chef' skit, which made ChuckleVision seem like an homage to Beyond The Fringe; some seaside vacation footage that, unless there was an in-joke that one was in on, was irritatingly aimless; and, of course, the seemingly endless succession of boobs and bums.

There were three basic phases to the phenomenon. The first, which ran roughly from 1978 to the early 1980s, focussed on random content, and was characterised mainly by a simple desire to entertain the troops - plenty of outtakes, the odd tease or taunt about various bodies in the building, and a few members of staff being good sports and having a laugh. The second phase, running through the mid-to-late 1980s, focussed on the interaction of form and content, and was informed by an eagerness among the editors to impress or surprise their peers with playful escapism, crafty parodies and eye-catching technical proficiency; and this was followed from the end of the Eighties onwards by a final phase, focussing on thematic content, which saw the tapes grow more serious and satirical as the industrial anxieties, insecurities and grievances accumulated and the workers raged against the machine.

Looking back on them now as a whole, these two decades of seasonal tapes seem like a lifetime compressed into a handful of annual instalments, capturing the transition from innocence to cynicism, from energy to enervation, from hope to something very much like despair. They tell a tale of an industry jerking awkwardly from one internal culture to another, as a community gives way to an association, and the old bonds begin to break.

They also provide an intriguing insight into how, for a while, some of those who provided us with entertainment also provided entertainment for themselves. In these tapes, especially those from the first few years, we can witness what gave them a secret smile (as well as spot some of the emerging techniques and subversive styles that would be seized on subsequently by the likes of Not The Nine O'Clock News, The Kenny Everett Television Show, The Day Today and Brass Eye).

A sign of how quickly the seasonal tape established itself in the culture of the BBC was the number of performers who started reacting to their own mistakes by looking at the camera and saying: 'Merry Christmas, VT!' (and certain other actors, such as Maurice Roëves - who was playing Hitler at the time in a serious drama - began volunteering their own comic ideas for inclusion).

A sign of how quickly the tabloids spotted the tapes' potential for sparking controversy were the 'shock-horror' stories they manufactured just as soon as they could get their sweaty hands on a spare copy.

The first tape, for example, had featured a short clip of Princess Anne being interviewed by the sports presenter David ('One-Nil!') Coleman, now edited for comic effect:

DAVID COLEMAN: Have you yourself ever experienced any sex?
PRINCESS ANNE: Not... that it, no... I don't think so. I mean, it is possible on one or two things.
DAVID COLEMAN: What about Mark Phillips?
PRINCESS ANNE: Well, he says there's nobody he'd rather be beaten by than me.

Tame though it now seems (partly because the conceit has since become such a common TV comedy technique), this was promptly seized upon at the time by the hacks at The Sunday People and turned into a dramatic-looking front page story - shouting awkwardly: 'ANNE TELLY SPOOF SHOCK FOR BBC' - that spread like a rash over the rest of the red tops. Attracting the attention not only of the bosses but also a seasonal assortment of watchdogs (such as the BBC Governor Mrs Stella Clarke, who rushed to register the fact that she found 'the whole idea distasteful'), this swiftly switched the attitude of some of them from seeing the party tapes as just a bit of harmless fun to regarding them as a worryingly unpredictable source of mischief.

It also did not help that the packages started to be widely pirated, and, notoriously, were not only found piled up under the counter in one of the many poky video shops on the Tottenham Court Road, but were also being traded in the pages of the eBay of its time, the Exchange and Mart. Another compilation, entitled The Biggest Boobs Are on the BBC, was then discovered being offered for purchase on Shepherd's Bush market (copies of which were actually picked up by daughters of BBC executives), and also popped up, so to speak, as part of some sex tapes that were being sold out of a suitcase on Camden High Street.

This was not merely an embarrassment to the BBC, but it also - thanks to the fact that so many of the clips had been used without the formal permission of their participants, and the rights to the US material had blatantly been infringed - scared its legal advisors half to death. The word thus went out that something, urgently, had to be done, and done it was: Grant Watkins was abruptly 'relieved' of his responsibilities (he went off to work in New York), and the surviving staff were warned that there must be no more of this sort of thing.

What followed was rather like an internal game of Whac-A-Mole, with the upstairs enforcers looking to shut things down and the downstairs enablers finding new ways to keep them up and running (re-naming them as 'training tapes' was one ruse that worked), until, after a while, the bosses got bored and turned a blind eye (including the then-Managing Director of Television Bill Cotton, the man who had formally banned them but who privately always relished watching them) and the workers (now led by the well-respected Dave Rixon from the comparative safety of a special hidden location) were left once again, more or less, to their own devious devices.

When reflecting on the more controversial aspects of these Christmas capers, however, we should resist the now all-too common tabloid revisionism that strains to suggest that while a solitary dark cloud of moral turpitude hovered motionless over Television Centre, Disney-style angels fluttered over all of the commercial companies flickering sparks of sweetness and light. What actually went on in one place, good and bad, tended to go on in all places.

This was certainly the case as far as the seasonal VT tapes were concerned. While the federal nature of ITV worked against any collective and cohesive initiative, there was still plenty of enthusiasm to emulate their BBC counterparts among the individual regional companies, who started seeking ways and means of coming up with a similar mixture of slip-ups, slap downs and sauciness.

London Weekend Television (which had always employed some of the best editors) had actually preceded the BBC as far as putting private 'entertainment' tapes into circulation, but most of these had contained such a high quotient of smut (far more, indeed, than one would ever find on the BBC collections) that they belonged more to the old stag movie genre than to the more recent VT enterprise. Once they had all seen and studied the style that Grant Watkins had fashioned over on 'the other side,' however, the commercial teams wasted no time in copying the concept.

From Anglia to Westward and TSW, Yorkshire to Granada, Southern and TVS to Grampian, someone or other was now busy saving the shavings furtively from the factory floor, piecing them back together, mixing some of them up, and then storing them away for their own Christmas party surprise. Suddenly, offices and editing suites in broadcasting centres all around the country were flickering away on a dark December afternoon or evening as the staff surveyed their own light-hearted take on the last twelve months in television.

There were even friendly competitions (hosted initially by Countdown's Richard Whiteley) organised each year between BBC and ITV tape editing departments in which all of their latest efforts would be screened and scored Eurovision-style. 'It's just a sort of Christmas joke,' said London Weekend Television's Bob Cockerell about such contests, 'a bit of fun for the lads'.

One of the negative consequences of such growing competitiveness, however, was a certain coarsening of what passed as 'fun for the lads'. As if driven by the premise that, in the manner of a pavlovian response, the sight of a bare breast was guaranteed to trigger a loud and leery cheer, the amount of (invariably female) nudity soon shot far past the 'normal' numbers like the knobs on Nigel Tufnel's amplifier, and, led along the line of least resistance, many of the editors became fixated on coming up with the taped equivalent of a lads' mag brand of laughs.

One of Southern TV's efforts, for example, featured a skit on its cheap and cheerful children's show The Saturday Banana, with someone made-up to look like the infamously prickly host Bill Oddie (or 'the poison dwarf' as such tapes tended to refer to him) sitting in an armchair while a stripper, dancing to the show's jolly theme tune, performed a succession of lewd acts on the fruit in question. The backroom boys at Thames TV, inspired by the same corruption of innocence scenario, produced a sexual innuendo-stuffed version of the lunchtime children's series Rainbow, with Geoffrey, Bungle and the always creepy-sounding puppets George and Zippy all encouraging the audience at home to 'play with their twangers'.

Meanwhile, over at Central, the darts-based 'super, smashing, great' game show Bullseye suddenly came over all potty-mouthed (Jim: 'Now, Andy, you're from Cockermouth. Is that where you live or is it just your hobby?' Andy: 'Just a hobby'. Jim: 'Are you gay?' Andy: 'Gay? I'm not even fucking happy!'). It was much the same at the end of another year back at Thames, where the thin white toot Jim Davidson provided some in-house stand-up about 'knickers' and 'thrupenny-bits,' a Blue Peter parody ended up with a woman removing her stockings and, in a separate spot, someone else stepped forward and posed topless.

Yorkshire TV joined in with some dubious clips from its own game show 3-2-1: 'This is about eight inches long...Caroline and Linda regularly have one in their hands...I've got one, and mine weighs about two pounds...It can stand up on its own...and I'm going to give one of you one right now'.

Even the news service ITN got in on the increasingly bawdy act, with Christmas compilations that featured a very drunk Ian Botham discussing the soreness of his 'ring-piece' whilst dangling a dessert spoon down some unknown woman's cleavage; a male reporter being forcibly stripped; the veteran Labour MP and front bench bruiser Denis Healey ordering a film crew to 'put your fucking light on'; newsreader Jon Snow being surprised by a whoopee cushion; the TUC's current capo di tutti capi Len Murray snarling at an interviewer 'I'll have your balls for breakfast'; and some 'amusing' footage of various gunfights and explosions in various war zones.

Only the stern-faced Knoxian brood up at STV, who featured some outtakes from a curling contest and a netball game, along with a guided tour of an OB van, managed to suggest that little had happened over the course of their year that was particularly louche, lascivious or, indeed, humorous. Even they, however, found the space to include a spoof commercial for wholemeal condoms.

Some of the festive tapes (especially the ones made within the Corporation) also became increasingly self-referential as time went on. In one effort, for example, one of the VT team played a member of the public who was an obsessive collector of VT Christmas tapes, while various BBC personalities, including the film critic Barry Norman, reflected in a straight-faced way about the whole VT Christmas tape phenomenon. It was all quite clever, and certainly a welcome change from the usual post-pubescent prurience, but, as time went on, they seemed, increasingly, in grave danger of disappearing straight up their own A-rolls.

Eventually, the tapes became the victims of their own success. Once a fast-growing number of executives realised how popular such outtakes could be, they did not want them 'wasted' on their own staff and so started putting them straight into their own shows instead, such as Auntie's Bloomers, Outtake TV, TV Nightmares, TV's Naughtiest Blunders, TV Offal and the evergroan It'll Be Alright On The Night. The inversion had thus itself been inverted, and what passed as entertainment off the screen was now folded back into being entertainment on the screen.

As for seasonal staff entertainment, once the more businesslike era of Michael Checkland and John Birt had fully contaminated the culture (which was now about as welcoming to the idea of in-house Christmas entertainment as Oliver Cromwell's policy was to local neighbourhood wassailing), the workers were expected to tick to the tock of the time and motion specialists, and it became dangerous to be seen dawdling among the detritus. Although this would actually have a clumsily counter-productive consequence - there was now no release valve to prevent the pressure cooker from going pop - there was something grimly inevitable about its arrival.

It is sad, nonetheless, to reflect on the gap it has left. The BBC (much like Oxbridge and other big and venerable organisations) is an institution that has always tended to fawn over those who are clearly just passing through, whilst shamelessly neglecting those who remain and actually believe in its defining ideals. Appreciating and supporting each other's efforts, through occasional informal and self-sponsored gestures, is one of the few ways whereby those who are taken for granted can actually feel that their labour and loyalty are still, in spite of it all, worthwhile.

'Welcome to the Christmas tape', they sang on the 1995 offering. 'It's our only laugh'. The Christmas VT tapes certainly had more than their fair share of flaws - from lazy clips, bad acting and karaoke caterwauling to signs that, quite frankly, some of those who made them had simply watched far, far, too much television for their own, or anyone else's, good - but, at their best, they gave some of broadcasting's most essential but undervalued people some much-needed festive cheer.

The message seems much the same whatever your business happens to be: if you really can't give your staff a raise, or even make more of an effort to treat them with a bit more kindness and respect, then at the very least you should give them some space to air and share their complaints, and, while you get on with your own Christmas parties, leave them alone to get on with theirs.