Hugh Bonneville will return as the incompetent former head of the Olympic Deliverance Commission in a sequel to BBC2's acclaimed comedy Twenty Twelve – and this time he is in charge of the future of the BBC.

Writer John Morton will resurrect the main character of his popular and critically lauded Olympics sitcom in the new four-part comedy, W1A – the postcode of Broadcasting House, the corporation's central London headquarters – described as a "love letter to the BBC" in which Bonneville's Ian Fletcher is installed as the corporation's new head of values.

Once again mirroring real life events, his (entirely fictional) job is to define the core purpose of the BBC as it gears up for charter renewal and a new licence fee settlement in 2016.

Aware of the potential pitfalls of a BBC comedy about the BBC, Morton said: "It isn't a demolition job on anybody or anything, and it isn't one giant in-joke, and this isn't a game of guessing who is supposed to be who.

"If it is satirical then it's satirical about an environment, an ethos, and the absurdities of modern corporate life itself. The key principle is to operate at a level of reality just to the left or the right of fact, to create stories that haven't actually happened but that could happen or might have happened."

Bonneville is not the only star of the Bafta and Broadcasting Press Guild award-winning show to return in W1A, which will also feature PR guru Siobhan Sharpe, played by Jessica Hynes.

Mark Freeland, head of BBC in-house comedy which will make the new series, said: "This is a kind of love letter to the BBC. But a letter that gets mislaid, because the remote computer system is not working and head of recovery, BBC, is stuck in a blue sky brainstorming session in a meeting room that's been double booked and anyway, the bean bags have gone missing."

W1A was commissioned by BBC2 controller Janice Hadlow and controller of comedy commissioning Shane Allen. Filming begins next month.

The BBC said: "The post [of BBC head of values] is sold to Ian as a chance to influence and shape one of the great British institutions.

"His job is to think 'big thoughts', but it doesn't him take long to realise that not only does he not have time to think big thoughts, he never has time to think any thoughts at all."

Hadlow said: "Twenty Twelve was one of BBC2's stand out comedy hits last year and I'm absolutely thrilled that John Morton and the fantastic off-screen team are coming together again as well as some of our most loved characters from the first series."

Reuniting the team behind Twenty Twelve, W1A will be produced by Paul Schlesinger and executive produced by Jon Plowman.

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