By Mike Polanyk

Breathe easy. Everything’s okay. They haven’t screwed it up. BBC’s savagely funny political sitcom The Thick Of It has been turned into a film, without  losing a single drop of the  scabrous wit that made us love it in the first place.

And that, surely, is a first.

Think of other British sitcoms that have tried to leap the chasm between the small screen and the big – Rising Damp, Steptoe and Son, Dad’s Army and – shudder – Are You Being Served?

Put them out of your mind again, quickly, and let’s move swiftly on. Award-winning satirist  Armando Iannucci delivers a stinging slap to the political establishment in this sardonic, foul-mouthed spin-off, which crams more belly laughs into its first 20 minutes than most comedies manage in two hours.

To say the script is polished to perfection and peppered with dazzling one-liners would be an understatement.

The only danger is that you’ll be guffawing so hard at some of the gags, the next punchline will be lost amid the delirium.

Some of the protagonists from The Thick Of It are resurrected here, but the film stands alone as a biting indictment of blather and bluster.

In the eye of the storm is tenacious communications chief Malcolm Tucker (Peter Capaldi), who is hurriedly called into action to minimise the damage caused when the  Secretary of State for International Development Simon Foster claims that a US and British-backed war is “unforeseeable’’.

Foster (Tom Hollander), compounds his blunder by giving a second TV interview.

“To walk the road of peace,’’ he blunders, “sometimes we need to be ready to climb the mountain of conflict.’’

Tucker is aghast: “You sound like a Nazi Julie Andrews!’’

At the insistence of the Prime Minister, Foster heads for Washington accompanied by new aide Toby (Chris Addison), while director of communications Judy (Gina McKee) papers over the cracks back home. Foster soon finds himself embroiled in a tug of war between the pro  and anti-war factions, the latter spearheaded by US Assistant Secretary for Diplomacy Karen Clarke (Mimi Kennedy) and US General Miller (James Gandolfini).

While Tucker tries to prevent his man in a suit saying another word and embarrassing the British Government any further, Toby woos Clarke’s ambitious intern, Liza (Anna Chlumsky).

In The Loop could have been another of those movies that are praised to the hilt at film  festivals, then turn out to be nowhere near as good as we were led to believe when they finally go on release.

However, Iannucci’s film – think Yes Minister on heat – is every bit as good as you’d hope.

Well, almost. I can’t help feeling this would have worked even better with a bigger budget, a starrier cast and a longer running time.

But let’s not quibble too much. This is a British film which taps into a long, deliciously dishonourable tradition of vicious political satire.

Capaldi steals the show with a virtuoso performance. There’s even a moment of happy serendipity when Hollander’s lovable klutz of a politician reveals he dare not watch an adult movie on the hotel TV system in case he has to declare it.

It’s hilarious. If only the backers had dug a little deeper into their pockets, we would have had a classic.

Rating: 4/5