The Royal Bodyguard is the brand new comedy series from writing, directing and producing team Mark Bussell and Justin Sbresni. After careers at both ITV and the BBC, they've a long list of credits to their names including the hit BBC One sitcom The Worst Week Of My Life, which has been sold to and remade in more than 120 countries worldwide. Here they are joined by Sir David Jason, who stars as Captain Guy Hubble in the new show, and executive producer Jimmy Mulville to discuss the series.

Mark explains what inspired them to write The Royal Bodyguard: "We wanted to create a family show. There's so much comedy that has a definite edge to it, like Curb Your Enthusiasm, The Office and Family Guy, and they're some of my favourite shows. But you can't really sit and watch them comfortably with your granny or anyone under the age of 14 at one time. There aren't many shows like that around at the moment."

Justin agrees: "When we were growing up there were classic programmes like Dad's Army or Some Mothers Do 'Ave 'Em, which were real family viewing. Nowadays there are shows like The X Factor and Strictly which families congregate around the television to watch as a group, but there aren't many comedy shows. Mark and I have families of our own, and we wanted to write something that we could all watch together. In the last few years many comedies have been pushing the boundaries, very dark and risque. That's not what we're doing.

"The Royal Bodyguard is a show about a heroic character who is out of his depth. Some people might look at Hubble as being rather incompetent, but he always gets the job done - albeit in rather an eccentric way - and wins in the end. But the journey to that victory is strewn with all sorts of problems."

Mark elaborates: "Hubble possesses a set of virtues that might seem somewhat out of keeping with modern society - a blind sense of loyalty and duty and a wish for things to be done properly."

Justin: "They are very traditional values in the setting of the Royal Family: patriotism, loyalty. We didn't particularly want to be cutting edge, because the Royal Family isn't. You don't sense that the Queen is using an iPhone! We quite liked that timeless quality."

Mark and Justin wrote the series with no-one in particular in mind so were delighted when BBC Comedy Commissioner Cheryl Taylor told them that they would like to show the project to Sir David Jason, who they wanted to entice back into comedy at the channel.

Justin explains: "We didn't know David was ready to come back to comedy. He had been doing A Touch Of Frost and all sorts of other wonderful ITV dramas and it didn't occur to us that he might star in our series. Of course once his name was suggested his commitment to physical and visual comedy, which is something we love as well, seemed like an incredibly exciting opportunity, as it has proved."

Mark adds: "David said that if there was one part that he would have loved to have played, it was Inspector Clouseau. So when he read our script, he could see the same DNA cord, and I think that really excited him. He is also of course associated with some of the most loved visual gags in recent television history, so he knows he is good at it and relished the opportunity to do more."

Thinking about David Jason's aptitude for physical comedy, Justin recalls: "We first got to know about David Jason towards the end of the '70s when we were just old enough to remember A Sharp Intake Of Breath and The Top Secret Life Of Edgar Briggs. Then Only Fools And Horses and Darling Buds Of May brought him firmly into the public eye. But we hadn't realised that David had honed his craft as a physical comedian in the theatre in the late '60s and '70s and he is incredibly good at it. I think he spent about ten years perfecting his skills on stage, including 18 months in No Sex Please, We're British at the Aldwych Theatre, during which time he threw himself around night after night. He is like an athlete really. He knows exactly how to fall and bounce back and we don't know many actors who can do that. So he was ideal for this part, because it is very physical humour. There is a lot of farce and a lot of visual comedy in the series. It's what we enjoy watching, writing and producing as well. We enjoy writing stuff that gets a big reaction - which physical comedy tends to, when you get it right."

Mark laughs: "David's age was also an advantage - having an action hero who is over the age of sixty was, in the end, funnier than casting someone who might traditionally be in their forties.

"It's the most ambitious thing Justin and I have ever done. These are six little films really. David is obviously a brilliant comedy actor and once we knew he was committed to the project we could have fun writing with him in mind. This series gave us the chance to show his incredible versatility."

Justin says: "The key difference between this and The Worst Week Of My Life is that Hubble is more successful, a winner, whereas Howard sort of won right at the end of the series, after a catalogue of failure and disaster after disaster. The stakes are much higher, initially because national security is at stake, rather than one man's relationship with a family. One of the reasons why he's a Royal Bodyguard is that when you've got something going wrong in a comedy, you want the stakes to be as high as possible. And it doesn't get much higher than royal security! So Hubble gets a very responsible job following a chain of events that are misinterpreted. The Queen takes a shine to his achievements, especially after he saves her life, and gives him the job and nobody can really trump The Queen. Once he's there, despite the fact that there are various people who are his immediate bosses who think he's a complete twit, they can't get rid of him."

Mark and Justin enjoyed working with Jimmy Mulville of Hat Trick Productions again. Justin says: "He's a huge fan of visual humour, a real enthusiast. And Cheryl Taylor of the BBC is also into physical comedy and was looking for big scale, ambitious comedy along the lines of Some Mothers Do 'Ave 'Em. So we felt well supported."

Jimmy was thrilled when David Jason agreed to star in The Royal Bodyguard: "I worked with him in 1978 when I was a baby radio producer and he was in Week Ending, and once he was on board we could develop the scripts with him in mind.

"It's family fun, and it's not in any way a satirical piece. It's about a man who has been promoted to a level just above his competence, which audiences will recognise. Each week we see David looking like a swan, very confident on the surface but pulling like crazy underneath!

"It's a show that you can sit down and watch with your family - it's just like sitting in a warm bath. You can lie back and let it wash over you. It's beautifully performed and we have some really fantastic character actors. As a producer I always say that if you have a great script you will always attract great talent and the ripple effect of that is that people do want to be in the show. We were lucky enough to get a star like David Jason and everyone followed."

He may have starred in numerous specials since, but The Royal Bodyguard marks 71-year-old Sir David Jason's first full comedy series for the BBC since Only Fools And Horses Series 7 in 1991. David explains what drew him back: "I've never really left comedy. It's just that I was asked to do some other things which interested me, which started with Darling Buds Of May and from that came Frost. But with everything I have done I have tried to make sure there's some comedy in it. I was offered various parts once Frost came to an end, but nothing was really of any interest until this script came along and I just thought it was very funny.

"Hubble's a boulder short of a coast line. His heart is in totally the right place, he's just a wonderful character, but it's all happened by default and accident. He's also got a very old-fashioned sense of duty. He doesn't know that he is inadequate. It's everyone else who are not up to their jobs. The three other lead actors are so good at playing it straight that it makes my job so much easier because my character is so inept, so daft sometimes that the thing that holds it together, the glue, is his opposite numbers, played by fantastic actors.

"One of the strengths of the show as far as I'm concerned is that my immediate bosses, led so brilliantly by Geoffrey Whitehead, lend such gravity and dignitas to any situation, such a reality which really makes me laugh; their weight, truth and solidness means that the scrapes Hubble gets himself into, well, they give them a much greater truth. But Hubble totally has the ear of the Queen and every time his boss wants to fire him, she calls him to say how thrilled she is with his work."

Jimmy laughs: "Hubble is a military man through and through. His father almost killed Winston Churchill, so it runs in the family! He has the purest of intentions but he just doesn't back it up with anything. The thing about this character is that he's loveable because he cares about his job, he cares about his country, he's got lovely, impeccable values. It's just that lethal combination of incompetence and enthusiasm. We've all worked with people like that. It's a complete nightmare! Hubble gets up in the morning to do a serious day's work; the fact is that he keeps putting his foot in it and he just keeps on digging, he just doesn't know that he is facing the wrong way!"

Justin agrees: "He's very confident but he doesn't really think things through. He's taken orders for 30 or 40 years and now he's in a position where he has to take the initiative himself, and he's just not used to it..."

David relished playing the part. He says: "This is very visual comedy. It's the sort of television we've lost sight of maybe. There's plenty of hard-hitting comedy and drama out there, and that's fine, but we feel there if room for this old-fashioned, timeless style. People still love Laurel & Hardy and Morecambe & Wise, and Tommy Cooper. It's simple but very, very funny."

Jimmy adds: "The Royal Bodyguard is a celebration of innocence; we see Hubble walking towards a cliff edge every week and we're screaming at him 'Don't go there!' It harks back to the sort of old world that doesn't exist anymore, where people have fantastic values and a real sense of duty, and then the real world intrudes - we have a siege and a theft for example - but then the lovely world is repaired at the end of each episode.

"There's a Peter Sellers film called The Party. The lead character is fired from a film set because he's a terrible extra and the producer says he never wants to see the man again. So the secretary puts his name on a blacklist. But she's accidently written it on the paper underneath, which is a party guest list. So the idiot is invited to the party and of course he wreaks havoc. What's happened here is that this particular fool has been invited into the inner sanctum of the Royal Family by error and his boss, played by Geoffrey Whitehead, knows that he is a ticking time bomb, but somehow he manages to get it right in the end."

David met the Queen when he received his knighthood: "She is very polite, very nice, but she didn't enter into conversation. She did ask me what I was doing next and I was such a fool. I said 'I'm doing the Christmas special of Only Fools And Horses' and I felt a bit of a wally. I do think she's got quite a good sense of humour and I don't think she'll find anything to be offended by in this. It's a very affectionate portrayal. Hubble would take a bullet for her!"

As for the kind of comedies that he likes: "My daughter, my wife and I all love Miranda Hart. I like her because it's wonderfully old-fashioned humour. I also really like Michael McIntyre. You're safe with him. He is so clever and observant, very physical, walks around and brings his jokes to life. He doesn't just stand there and tell jokes and take the p**s out of the audience. I recently saw him do a simple joke about the way people behave when they are caught in a traffic jam and I absolutely knew what he was talking about."

Jimmy adds: "I have noticed an appetite from the broadcasters for this kind of show. Shows that families can gather round; ITV want pre-watershed sitcoms, Sky are buying comedy real estate like it's going out of fashion. BBC One want more. There's a yearning for shows that make you feel good - maybe that has something to do with the recession."

David agrees: "Tommy Cooper and Morecambe & Wise have funny bones. You just have to look at them and you start giggling."

Mark agrees with their sentiment: "Dad's Army and Open All Hours are decently constructed, they're not about effing and blinding. Call me old fashioned, but if I'm watching a comedy, I'm looking for an involuntary response over which we have no control and it's called... a laugh."

David says: "I learned most of my craft from being on stage. I took over from Michael Crawford in No Sex Please and they were some of the happiest times of my life. I love being on stage. There's nothing like hearing a full house really falling about laughing at your antics - that's what drove me into this business. It's a wonderful feeling, the best drug in the world.

"The Royal Bodyguard was great fun but very hard work. Some of the things they made me do! We had a brilliant stunt co-ordinator and a stunt man to do the very tricksy things, but I still get thrown into mud and fall into tanks of water and I'm swinging on pipes and jumping down a chimney covered in soot. I got wrapped in cellophane at a spa and was cocooned in cling-film for the entire day - I couldn't get my hands on my lunch!

"I also got to wear a crown topper, one of those one-size-fits-all wigs you used to be able to buy over the counter. You put it on and tried to comb it and it looked like a bird had nested on your head. You still occasionally see elderly gentlemen wearing a wig he's probably had since he was 25-ish but his head has shrunk and his white hair is a completely different colour from the wig, which is a funny sort of fox colour which you can see coming a mile off. Nowadays people like David Beckham have made it fashionable to be bald or close shaven."

Turning to the rest of the cast, Mark says: "Timothy Bentinck plays a very British establishment character, Sir Edward Hastings, someone who wants to see the best in everyone, and there is a kind of bumbling amateurism to him, really wanting a quiet life. If there's any trouble and the Queen says 'Hubble can handle this' Hastings is not going to question that. The costume designer picked up on something quite nice. All of Sir Edward's ties are cricket ties of some sort - there's a sense of "It's just not cricket', a sense of the importance of fair play."

Justin adds: "Timothy's character brings a very interesting dynamic to the character of Hubble, because he likes him. That's really important - if everyone thinks Hubble is an idiot with no redeeming features, then the audience might do too. Hastings brought sympathy and warmth to the setting, which gives the series a bit more light and shade."

The Royal Bodyguard is the fourth project on which Mark and Justin have worked with Geoffrey Whitehead, as Mark explains: "He's an absolute joy. Jimmy described him the other day as the unsung hero of British comedy."

Justin agrees: "No-one is as funny as Geoffrey and as a foil to characters like Howard or Hubble, you have to have a disapproving character in a funny way. He makes a lack of sympathy very funny because he is so rude about Hubble."

Meanwhile, Tim Downie plays Yates. Mark Bussell says: "Yates is nearing the job he always wanted, but his ambitions are being thwarted by this man Hubble. He can see just how incompetent he is, and yet no-one else apart from Dennis can see it. So he has the double frustration of someone taking his dream job and someone who's not very good at it to boot, being congratulated on how well he is doing it. Tim plays that stewing resentment really well. It is thrilling for us to have a new face in the series."

Little Britain and Come Fly With Me star David Walliams will also make a guest appearance in the series, as Sir Ambrose, Surveyor of the Queen's Pictures.

Mark explains: "David Walliams is a big James Bond fan and has imbued his villainous character Sir Ambrose with a variety of Bond villains with their stony stares. He's very still, eyeing up Hubble with great disdain.

"David Walliams was a joy to work with and we were a kind of distraction for him from his swimming training of course as he was about to set off on his epic journey to swim the length of the Thames for Sport Relief. He did a few days with us then went off and swum another thousand lengths!"

David Jason found the experience of working with Walliams very interesting: "You see him in those sketch shows and he's so large and aggressive and plays such strange people that I was expecting him to be a bit eccentric, but he's totally the opposite. He's very polite and very quiet and well mannered, and he's also very good at what he does and I was delighted by all that. But it was a surprise when he came on the set for the first time and wasn't loud."

Sir David says he will be watching himself when The Royal Bodyguard screens: "I'm not a great fan of doing that because you get terribly haunted by bits that don't work and you think you could have done better, but I do like to get a sense of a first night, when others are watching. It will be me, my wife and daughter, because if I am surrounded by lots of people, every time they don't laugh it's like a nail in the coffin, and you feel that if they really laugh at something they're being polite. So experiencing the first episode going out live is a very haunting experience and not a pleasurable one, but it has to be done, sitting there with people all around the country watching you as the credits roll."

He concludes: "Making The Royal Bodyguard has been hard work and long hours. Physically it's the most demanding role I have done. It all starts with the script. Then you look for something interesting in the character and take it from there. Now it's out of my hands and we'll just have to see how the good old British public respond..."