An equalities minister who has voted against racial and sexual equality rights. Chuckle. A health secretary who supports homeopathy. Ha! It's good, this politics malarkey, isn't it? A right giggle. Some might think it beyond parody. But thankfully not The Thick of It crew, who, three years after its last series, returned last night with an eagerly awaited fourth to take on the calamity coalition.

First, the good. In fact, the excellent. Roger Allam as the Tory MP Peter Mannion, new head of Dosac - the Department of Social Affairs and Citizenship - fills the role perfectly. The floppy hair, the floundering as he tried to explain a "networked nation" that was beyond him, the barely concealed contempt for those he works with ("I'm bored of this," he said, walking out of a meeting with his junior minister. "I'm going for a Twix") and those he works for. ("I hate schoolchildren. They don't even have the vote. Might as well talk to fucking geese.")

Then there's the spin doctor Stewart Pearson, a lighter touch than attack dog Malcolm Tucker, all herbal teas, brainstorming and, in the words of Mannion aide Phil Smith, provider of "seven years of ear piss".

That Tories and Lib Dems might not get on behind closed doors has been the subject of satire ever since this bastard child of Westminster was conceived in May 2010, but it was moved on here to good effect. It reveals the flaws in the central characters and allows for the best line of the night, uttered by Ben Willbond as Lib Dem No 2 Adam Kenyon. "Landmark day," he said as Mannion finally destroyed the launch of the Liberals' "silicon playgrounds". "We bring in an idea, you like it, you nick it, you put two bullets in the back of its head. Snuff politics: you've got to laugh." And you did, you really did.

Yet not everything was quite so sparkling. Punchlines were occasionally heavy-handed and the ranting felt sometimes forced. Consider Lib Dem junior minister Fergus Williams's tirade at punchbag press officer Terri Coverley: "Now you like musicals. Well this is 'Tonight' from West Side Story, and I'm going to bring the bloody house down, so you can't rain on my parade, Funny Girl." Too contrived. Maybe that was the point, but it made you pine for the eloquent misanthropy of Peter Capaldi's expletive-fuelled Tucker. Luckily, he's back in episode two...

We have proof that The Thick of It doesn't, always, need Malcolm Tucker. He's not back until next week, in mournful bored opposition.

Meanwhile, the coalition is being eviscerated on screen as cruelly as in real life. Tory Roger Allam's stuttering, excruciating few minutes before a crowd of tech-wise schoolchildren - he's a happy Luddite but to others a "digitard", a word which will become as useful as "omnishambles" - is equal to any other three minutes of comedy this year.

And a fellow Tory lambasts Lib-Dem colleagues thus: "You're basically a couple of homeless guys we've invited to the Christmas lunch... don't whinge when we don't let you carve the turkey." Somehow, this week in particular, this resonates. Too many good lines to fit in even an entire piece; too much happy brilliance.

The Thick Of It makes a welcome, belated return for what looks to be its final series. The Coalition are now in power and Peter Mannion, introduced in Opposition as an old-school wet Tory with a distaste for modern politics, is now in office, alongside a thrusting young Lib Dem. The civil servants are the same (as, confusingly, is advisor Glenn, who seems to have conveniently switched parties between series). And the fearsome Malcolm Tucker: well, he's out, leaving an anger - and swearing - vacuum.

Tucker and the hapless Nicola Murray reappear in the second episode, but even there he's a muted version of himself and the show seems softer, less scabrous without his manic presence. Which is probably completely deliberate: creator Armando Iannucci seems to have rethought the show's satirical emphasis as well as the new political framework. The politicians on both sides seem almost vulnerable, but so do their advisors, none of them really having any clue about what they're doing anymore.

It's still very, very funny and the cast are all perfectly pitched. Roger Allam, as Mannion, has such delicious comic timing that a simple line about a Twix made me rewind three times just to savour it again. One could quibble with the sheer amount of vituperative nicknames that the characters hurl around at each other - you have the impression that they must all be sitting up at night drafting new ones for the next day - but at least they make sense, unlike their policies.

All is right with the world, The Thick of It is back to wade through the mulch of coalition politics. The new Secretary of State at the Department of Social Affairs and Citizenship is Peter Mannion, looking as ever as if he hasn't actually got dressed, his clothes have fallen on him from the sky.

Mannion was an inept opposition politician and now his chronic lack of connectedness leads him straight into an appalling gaffe at a school when he tries to launch an apps initiative to a group of switched-on teenagers.

Roger Allam is laconically brilliant as Mannion as he lurches from one crisis to the next; if he isn't debasing himself on the phone to his furious, neglected wife he is grappling with his paisley-shirted spin doctor and his hated junior minister. Every line is quotable in what is 30 ruthlessly clever minutes of comedy treasure.

The first episode of the new series features one shocking absence - Malcolm Tucker languishes in opposition and is nowhere to be seen as yet - and of hints that the compromises of coalition are an open goal to for satirists. A botched schools policy dominates the opening episode. It's the brainchild of the Coalition's junior partners but - at the behest of fearsomely irritating spin doctor Stewart Pearson (Vincent Franklin) - it's launched by Roger Allam's crusty traditionalist Peter Mannion, who palpably neither knows nor cares about the initiative. Before long, Mannion's taken his daily 'gaffe dump' and is branded a 'fibre-optic Fagin' - could the government really be proposing the idea of getting kids to design apps to pay for their higher education? As you may have gathered, many of the names remain the same, they're just on different sides of the government/opposition equation. But some things never change. Still bumbling along in the background - hilarious, admirable, pitiful - are civil servants Glenn Cullen (James Smith) and Terri Coverley (Joanna Scanlan). Terri wants out but she's 'too expensive to get rid of.' Glenn is sadder still - when his new colleagues aren't ignoring him completely, they're comparing him to 'a week-old party balloon.' Yet does Glen hold the key to the show's essence? Glenn loses every battle he fights...

On balance the BBC probably picked the worst week to launch the new series of The Thick Of It. Because no matter how funny the opener was it could never have been as amusing as the fallout from David Cameron's Cabinet reshuffle.

Of course, you may question how anything in life could possibly be funnier than Peter Capaldi's potty-mouthed spin doctor Malcolm Tucker - and you'd be right. But Tucker wasn't in it. And neither was Rebecca Front's Nicola Murray, his most recent sparring partner.

Still, as a scene-setter for the new Coalition era it did manage some laugh-out-loud moments. And the return of Roger Allam's gloriously withering Minister Peter Mannion was most welcome.

Although, not as welcome as the trailer for next Saturday's episode. Because Tucker is back. Murray is back. And the hair of Chris Addison's oily Ollie is insipidly slicked back. Happy (expletive deleted) days, as Tucker might say.

Armando Iannucci's political satire returns for its fourth series - the first since Labour was ousted from government - and the good news is that it's still brilliant. The MPs, advisers and civil servants of the Department of Social Affairs and Citizenship are now working for a coalition government yet, unsurprisingly, are no more effective at their jobs. The department has created a new digital project aimed at teenagers but spin doctor Stewart Pearson (Vincent Franklin) decides that it should be launched by the Secretary of State (Roger Allam) - a man who has not only had no involvement in its development but is also digitally illiterate. Sadly it's a Peter Capaldi-free episode but he returns next week.

Cabin Pressure is one of the best written, cast, acted and directed comedies on anywhere.

Although only radio can make us picture exactly the single old plane on which this little airline depends, only John Finnemore's pen plus the sublime talents of Stephanie Cole, Roger Allam, Anthony Head and Anna Crilly could, last Friday, raise a salutary barrier between the turbulent real world on either side of their glorious fiction. Produced and directed, brilliantly, by David Tyler for independents Pozzitive.

Another new episode of a refined sitcom that bathes in a ridiculously good cast: alongside writer John Finnemore are Stephanie Cole, Benedict Cumberbatch and the man I refer to simply as 'The Guvnor', Roger Allam. This one's a bit special, boasting as it does the sort of tricksy, quadruple-crossing story that comedy writers often like to attempt but don't usually have the sheer plotting muscle to pull off. Finnemore has those chops. When Carolyn (Cole) entrusts Martin (Cumberbatch) to stop Douglas (The Guvnor) stealing some expensive whisky, a mystery worthy of Miss Marple unfurls. Sadly, Martin's investigating it instead.

I must admit that this is the first time I've listened to Cabin Pressure, despite all of the reviews and praise that has been lauded on it.

For those who, like me, still haven't got around to listening, this show is about MJN Air, the world's smallest airline, managed by Carolyn (Stephanie Cole) and flown by Captain Martin Crieff (Benedict Cumberbatch) alongside First Officer Douglas Richardson (Roger Allam). The service on the plane is provided by Carolyn's over-enthusiastic son Arthur (played by John Finnemore, who also writes the show).

The first episode of the third series saw MJN flying some people to Qikiqtarjuaq (near the North Pole) to look at polar bears, which got Arthur both excited and annoyed - excited about the bears, and annoyed about that none of the Q's in "Qikiqtarjuaq" are followed by a "U".

Elsewhere, the highlight for the show for me was Douglas making an announcement to the passengers while smuggling in as many Alfred Hitchcock references as possible. Also, Douglas forces Martin to pretend to be French and recount to the plane how he fought off a polar bear using nothing except an egg whisk and a pogo stick.

Having listened to the show I feel slightly ashamed by the fact that I missed the first two series and now feel a desperate need to catch up - which I'll have to do at some point in the future when I'm not writing these reviews.