The makers of BBC Two hit Twenty Twelve have found a new target for their satirical gaze: the broadcaster itself. Hugh Bonneville tells

Jeananne Craig why the corporation is right to show its sense of humour

He’s recognisable to millions of TV fans around the world as Downton Abbey patriarch Lord Grantham, and appears alongside the cream of Hollywood talent in new film The Monuments Men.

But global fame didn’t stop Hugh Bonneville falling foul of the BBC’s security system while shooting new comedy W1A at the corporation’s London headquarters.

“We were filming in the lobby the other day, 20 of us milling around, and the chaps on the doors were chuckling watching us do it. Then I tried to get back inside to get changed and they wouldn’t let me because I didn’t have the right pass,” he recalls.

“Jeremy Clarkson tells me he wasn’t allowed in either. People who’ve worked here a long time will know what I’m talking about; the bureaucracy of the machine is part of the thing that is so lovable about it.

“And so confusing,” the actor adds with a laugh.

London-born Hugh is reprising his role as the rather bumbling boss Ian Fletcher in W1A, a spin-off from the award-winning Olympics mockumentary Twenty Twelve.

Filmed amid the bustle of Broadcasting House, W1A sees the BBC turn its satirical sights on itself.

Ian, former head of deliverance for the London Games, has a new and equally vague job title as the broadcaster’s head of values as it gears up for charter renewal and a new licence fee settlement.

As with Twenty Twelve, the corporate jargon is rife. There are hot desks, digital handshake sessions, daily senior team damage limitation meetings, and a “balancing area” which consists of a huge orange see-saw (a prop, not a permanent fixture, presumably). On the day I visit the set, the BBC’s creative director Alan Yentob is sitting near the aforementioned see-saw, about to film a cameo.

Fictional crises discussed – and then discussed some more – in W1A range from Jeremy Paxman falling asleep during an interview with Scottish First Minister Alex Salmond, to claims by angry activists that Cornwall is under-represented by the BBC.

It seems like a brave move for the corporation to poke fun at itself – indeed, the new show was announced just a day after director of television Danny Cohen hit out at “the daily chorus of BBC-bashing that takes place in some quarters”.

Hugh thinks the organisation is right to show it has a sense of humour.

“I think it’s wonderful. In the same way Sebastian Coe got the joke about Twenty Twelve – that it wasn’t actually satirising the notion of the Olympics – and allowed us to film him, we’re not having a go at the BBC.

“We’re highlighting some of the strange corporate speak and corporate structures that go on in any organisation, be it a FTSE 100 or the village hall.”

He adds: “It’s certainly chuffed the art department to bits because they don’t have to do any set dressing, it’s all here. That’s also fantastic for the licence fee payer, because they’re not spending money on location.”

Filming in situ gives the show an authentic feel, but it can lead to some confusion, as Hugh reveals.

“We often use long lenses, so the camera will be quite far away. I had someone who reads the Radio 4 Shipping Forecast come up and start chatting to me, so I had to explain that we were in the middle of a shot. He had to gently edge away…”

Among those thwarting Ian’s attempts to get anything done are uncompromising head of output Anna Rampton (played to poker-faced perfection by Sarah Parish) and brand consultant Siobhan Sharpe (Jessica Hynes), whose utter ineptitude Twenty Twelve fans will recall with relish.

We also see Ian floundering without his trusty former PA Sally (Olivia Colman), who is replaced in W1A by a nice-but-dim intern, who can’t even master the coffee order.

Hugh, who lives in West Sussex with wife Lulu and son Felix, admits it can be difficult to stay straight-faced on set.

“What these characters tend to say is often really absurd, but they don’t know they’re being absurd. And when you’ve got someone like Sarah Parish telling you a load of nonsense straight into your face with a completely deadpan expression, it’s very hard not to crack up.”

As for a second series of W1A, Hugh confesses: “I don’t know whether we’ll be allowed to! We’ll have to see what the reaction is.”

It’s been a busy few months for the star. With filming on W1A wrapped, he’s now working on series five of Downton. And then there’s star-studded Second World War film The Monuments Men, in which he appears alongside George Clooney, Matt Damon and Cate Blanchett, among others.

“There isn’t a lot of time off at the moment but I’m not complaining,” says the well-spoken 50-year-old.

“Monuments Men, goodness me, it was all down to Downton Abbey I’m sure… I was fantastically nervous working with these great icons of the screen – some of my heroes, like Bill Murray and John Goodman and Jean Dujardin from The Artist, wonderful people. Of course, as soon as you get on set with them, you realise they’re just actors who want to do a good job too.”

The corporate sphere of W1A and the aristocratic grandeur of Downton Abbey are worlds apart, but the actor clearly takes pleasure in both.

“They’re both punishing days when you’re on the set, but with Downton, the pace is a bit steadier, because it’s a much bigger sort of machine and we don’t shoot as much material each day. Twenty Twelve and W1A are quite frenetic in their pace and the page count is quite a lot. The nature of filming is very different – one is faux documentary style and the other couldn’t be more sort of classical.

“I love the fact that there is that variety,” he adds.

But surely there are similarities between Ian and Lord Grantham, as both try to maintain order and hold things together?

Bonneville laughs. “I suppose Lord Grantham and Ian Fletcher are basically both just trying to run a big team and hoping that the wheels don’t fall off the vehicle,” he says.

“Yeah, that’s a fair comparison. They’re both men trying to get by.”

W1A begins on BBC Two on Wednesday at 10pm.