How can a sitcom starring actors as wonderful as Martin Freeman, Hugh Bonneville, Anna Massey and Amanda Root fail? Yet The Robinsons (Thursdays, 9.30pm) not only fails to be funny, it fails to be watchable. You don't need to be a TV critic to realise why. Only somebody with the title Head of Comedy at the BBC could miss the programme's major weakness. There is nothing wrong with the premise - Freeman plays Ed, the nice-but-useless son in an overachieving but nasty family. Nor is there anything amiss with the writing, although it has clearly been too influenced by the American hit Arrested Development. The problem is the acting.
A few years ago, Bonneville and Root had a bedroom scene in the one-off drama Love Again, in which he played Philip Larkin and she was his librarian mistress. It was touching, comic and entirely believable. In a recent episode of The Robinsons, the two of them were in bed looking through a photo album of family beehive snaps. As Bonneville gave due deadpan weight to lines such as "Another bee", Root mugged and swivelled her eyes as if she was in an Ayckbourn farce.
The show's failure should seem ironic to Freeman. Since appearing in the sitcom of the decade, The Office, he has starred in two flops: this and ITV's Hardware. It is as if The Office not only redefined the traditional sitcom, but killed it. Freeman need not worry - with The Hitchhiker's Guide to the Galaxy, he has become a Hollywood star - but it must worry the rest of his profession. They'll either have to master comic naturalism or face long periods resting. Their competition is no longer David Jason and Ronnie Barker, but the stars of Wife Swap and The Apprentice.
Being both naturalistic and funny is not easy, as The Thick of It (Thursdays, 10.30pm, BBC4; soon to be repeated on BBC2) shows. The director, Armando Iannucci, has gone to lengths to get naturalistic performances out of his cast. The writers - Iannucci and three other experienced hands - leave their scripts to be finished off by the actors, who are ordered to improvise. The episodes are filmed chronologically, and two cameras are kept running to pick up reaction shots. It is filmed to look like a documentary.
Iannucci's efforts are particularly noticeable because The Thick of It is an updating of Yes, Minister, one of the stagiest sitcoms ever, and the comfort zone into which the people of Britain would enter on Monday nights in the early Eighties to persuade themselves that nothing too terrible could be achieved by Margaret Thatcher be-cause the civil service's instincts were so craftily lethargic.
The coarseness of this new series implies either that Iannucci inexplicably believes politics has somehow got nastier since Thatcher's time or that Yes, Minister's writers, Antony Jay and Jonathan Lynn, got Whitehall wrong.
The minister no one says yes to in The Thick of It is Hugh Abbot, an incompetent, permanently tired new Labour placeman in charge of "home affairs" at the nebulous Department of Social Affairs. Abbot, who half fears the sack and half longs for it, is played by the BBC's current favourite, Chris Langham, whose long, drained features recall a raindrop trickling down a window pane towards the gutter. His Sir Humphrey is the government's enforcer, Malcolm Tucker, a nightmare combo of Peter Mandelson and Alastair Campbell. Tucker's main contribution to government is raising verbal abuse to new and baroque heights ("He's as much use as a marzipan dildo" is a mild example of his craft), and one of the jokes of the show is that no one else is quite as good with the obscenities. But, as played by Peter Capaldi, Tucker is too febrile to be engaging: Capaldi is fine at the psychotic ranting, but struggles to convey the charm we are assured Mandelson and Campbell can turn on when they need to.
At the end of a very bad day in episode one, Abbot strays into the main office and wonders where his staff are, to be told that it's 5.40pm and so they have all gone home. It is the kind of anti-public servant gibe we might have expected from Yes, Minister. Here, the civil service has contracted to a cynical special adviser, an overweight head of press who has come from a PR job at Waitrose, and a junior spin-doctor called Ollie, straight out of Cambridge. Governance has been replaced by spin, The Thick of It claims with no great originality, and the show's only spin on this idea is that the minister himself can't spin to save his life and preserves his sanity by being the departmental truth-teller.
It is hard for a New Statesman reviewer not to like a programme in which Abbot says: "I work, I eat, I shower and occasionally I take a dump. That's my treat. It really is my treat. That's what it's come to. I think, 'No, I'm not going to read the New Statesman. This is quality time, just for me.'" But I am difficult to please. I hated Yes, Minister for its urbane cosiness. This series replaces urbanity with profanity and cosiness with cynicism, and the result is more depressing and less comedic than surely was the intention. In The Office, Freeman played Tim as a decent guy, and his performance lit up the gloom of Slough. Perhaps he should apply for a role in The Thick of It, a naughty world that would be helped by a few good deeds.
Andrew Billen is a staff writer on the Times