Armando Iannucci has a ringing in his ears. He’s just back from the Sundance Film Festival in the States where his debut feature film as writer and director, In the Loop, had its world premiere. The film’s reception was so overwhelmingly positive that it became the ‘buzz film’ of the festival, a buzz which is still echoing around his faintly bemused head.

‘Yes, apparently there was a buzz,’ he says with perplexed disdain. ‘Saying it’s a buzz movie sounds better than saying it’s a tinnitus film, I suppose. It was hilarious, people were running around going “You’re hot!” in that way that only happens in films. Suddenly, hampers of foodstuffs that you can’t really eat appear at the hotel from Hollywood agents, that sort of thing.’

Until Sundance, Iannucci was a relatively unknown quantity both in the world of cinema and in the United States, but of course we lucky buggers on this side of the pond have long been aware of his talents. An iconic figure at the heart of British TV and radio comedy for the last decade and a half, the Glasgow born-and-bred funnyman has been responsible for some of the finest, most incisive satire to grace the airwaves in a generation, from seminal news spoof The Day Today through Alan Partridge’s various outings to The Thick of It, his brilliant expose of a spin-obsessed British government.

In the Loop can be seen as a big screen companion piece to The Thick of It, written and filmed in a similar style and featuring many of the same actors. Peter Capaldi’s awesomely vitriolic spin-doctor Malcolm Tucker (a thinly veiled Alistair Campbell) is once again centre stage, although this time the action swings between Britain and America in the diplomatic hoopla surrounding the build-up to a non-specified Middle Eastern invasion.

‘The more I read about how we stumbled into Iraq,’ says Iannucci, ‘the more I realised it was either a truly dreadful story that would make you depressed, or it’s hilarious because it’s just stupid. When I realised it was the latter, I had my story.’

The film pulls no punches on the ‘special relationship’ between Britain and America, with British politicians coming in for a real kicking.

‘Tony Blair and Jack Straw just got starstruck,’ says Iannucci incredulously. ‘They got a bit woozy and thought, “Hey, we’re in the White House, this is good, isn’t it?” and lost their dignity. I went to Washington to meet people who worked in the state department. They couldn’t understand what was in it for Blair. Normally deals are made and both parties get something, but us Brits got nothing.’

Not that the Yanks fare much better – the film evenly depicts the haplessness of government officials on both sides of the pond. Iannucci reveals that during his research, he was truly frightened by the levels of inexperience and ineptitude apparent amongst US officials.

‘Quite a lot of American government is run by very smart 23-year-olds who have degrees in things like Strategic Terrorism Studies, but don’t know what to do with a washing machine,’ he laughs. ‘We met one person who was 22 who was sent to Iraq to help draw up the constitution, and were told about a 23-year-old given the US government’s Central American budget to handle, because everyone else was busy.’

One reason for In the Loop’s success at Sundance was perhaps down to Iannucci’s unflinching look at the bumbling oafs in charge of both countries. It’s a view often expressed in Britain since the sublime Yes, Minister (of which Iannucci is a massive fan, and which The Thick of It is a natural successor to), but not a view frequently echoed by big movies.

‘I deliberately wanted to portray the Washington side in the same way I portray the British side,’ he says. ‘This is how it works, it’s a bit shambolic. On a day-to-day basis there are just as many rubbish people there as in any other institution. I’ve not really seen that done in movies before. The portrayal of Washington is either very noble or else very malevolent, and the truth is it’s just a little bit rubbish, full of people not fit for life outside bureaucracy.’

The cast, including Steve Coogan, Tom Hollander and James ‘The Sopranos’ Gandolfini as an American general, were put through their paces during the six-week shoot last year. Similar to the making of The Thick of It, In the Loop was partially improvised by actors.

‘With each scene we shoot it as scripted first, then put the script aside,’ says Iannucci. ‘Then I ask the cast to improvise around it, really to rough it up a bit, make it feel more conversational. There’s no magic formula. Sometimes I go for the script; other times a mix of script and improvisation. It’s labour intensive at the editing stage, but hopefully you arrive at something that feels, despite all that work, spontaneous.’

In the wake of the Iraq war there have been numerous films on the subject, but In the Loop is the first comedy take on events, something which Iannucci thinks plays in its favour.
‘There were so many well intentioned but deeply serious films based on 9/11 and Iraq,’ he says. ‘It seemed the American audience warmed to In the Loop because it was entertainment. Without being high-handed about the role of comedy, I think you can do comedy about big things and it doesn’t demean or make them less serious. Some of my favourite comedies are Dr Strangelove, The Great Dictator, M*A*S*H and Catch-22. They can be dark and brutal, but you can still laugh.’

Iannucci’s satire has never been overblown, but is always perfectly pitched, so the viewer isn’t entirely sure whether the whole thing could be true or not. In the Loop maintains that style wonderfully, and it’s a style that has often made Iannucci seem prescient, all the way back to Alan Partridge desperately pitching Monkey Tennis as an idea for a lowest-common-denominator show to a BBC executive. ‘I know for a fact that Monkey Tennis has now been pitched seriously about three or four times,’ laughs Iannucci. How does that make him feel, I wonder. Queasy? Proud? ‘It makes me feel mostly ashamed,’ he deadpans.

GFT, Thu 12 Feb, 7.15pm, 8.15pm; Fri 13 Feb, Cineworld, Renfrew Street, 6pm.