22 August 2012 Last updated at 09:56

Speedy return for The Thick of It after three year wait

The Thick of It started in 2005 and returns for a fourth series in September

It took three years for the political comedy The Thick of It to start production again. But each episode took less than four days to film. The cast and crew explain how the show is filmed three times faster than others.

James Smith, who plays special adviser Glenn Cullen, looks in his diary to work out how long each episode took to film. Three and a half days, he says. That can be 14 or 20 pages of script a day. Producer Adam Tandy calculates twelve minutes of a show are filmed a day. Rebecca Front, whose character Nicola Murray gets promoted to leader of the opposition in the new series, reckons one day 30 pages of script were filmed.

According to Front, that's a comparative sprint in television filming terms. When filming for detective drama Lewis she'll get through up to eight pages a day.

'This is very deliberately done in a more guerrilla telly style, 'she says.

'It's hand held cameras and everything is just caught. On Lewis there's lots of sitting and waiting for it to be lit.'

The Thick of It actors don't need for wait for their lighting, because there isn't any.

Joanna Scanlan, who plays the irritatingly unambitious civil service press secretary Terri Coverley, says the show's creator, Armando Iannucci, was ahead of the curve in changing how to film fictional tv.

'This brings up the essence of The Thick of It. It's enabled by technology. Armando was one of the first people to spot that you could make something very fast, with these cheap cameras with cheap locations and you don't need lighting anymore.'

Shaky cam

This style, similar to documentaries, where there is no lighting and a shaky camera effect are not just about saving money and time explains producer Adam Tandy.

'The reason we have two hand held cameras is to give a sense of immediacy. We could make the cameramen wear steadycam rigs and it would be a little smoother but actually, that slightly jerky quality is what we're after.

'The two cameras allow us to edit it because you need two shots of something to be able to edit it down. If we didn't have two cameras we couldn't do that because the action is very different. We don't give the actors marks to stand on. They are free to do whatever they want to do - so you have to give the cameras that same freedom.'

That freedom is appreciated by Roger Allam who plays MP Peter Mannion, returning as the new Secretary of State for The Department of Social Affairs and Citizenship.

'It is very freeing. You don't have to pay attention to continuity, like asking yourself 'when did I drink that cup of tea'. It's much more fluid. It isn't like shooting a master shot and lots of secondary shots, so that you're repeating the same thing again and again.'

Front echoes Allam's sentiment:

'It's much more relaxing to do because you are in the moment, you are being that person. Whereas if you are doing the scene again and again for different camera angles and you're having to catch a particular light and hit a particular mark on the ground, it's a different sort of challenge because you're then having to try and be as natural as possible in a very unnatural environment.'

Sweary dream

That freedom extends to allow the actors to improvise, although they conceded that very little of their ad libbing makes it through the edit suite to the show.

BBC Media Centre in west London is used as the set for the main ministry

New to the show this series, Rebecca Gethings, describes this as a very immersive experience.

'Improvs could go on for 20 minutes and it would feel like a big shouty, sweary dream.'

While filming was quick once it got going, getting it off the ground was a long drawn out process. The last series was in October 2009 and lots has changed since then, including a coalition government in the UK, reflected in the series. The biggest challenge to getting a fourth series of The Thick of It filmed was getting everybody in the same room at the same time according to Tandy.

He certainly didn't have to travel far for some of the filming as the offices of the main ministry building are actually BBC Media Centre in west London - Tandy's own office. Media Centre started being used as a set for the comedy at the end of the first series in 2005 because their original location had been demolished before they could film the final episode.

'Bizarrely the exact place where we decided to put the office is now my official BBC office, since I moved from Television Centre,' explains Tandy.

'So there's signs everywhere saying comedy which we have to go around and take down.

He never lets colleagues in Media Centre know that their office is about to become a set.

'Sometimes we shoot on Sundays because there's lot's of reprobate comedy people hanging around now that would just jeer at us filming.'

The Thick of It will be broadcast on BBC Two in early September.