Katy Guest: Even pervy Ken couldn't invent Jade's mum

I don't know whether it is the miserable January weather or whether celebrities are just not as resilient as they used to be, but this year's Big Brother house is proving far too taxing for its latest residents. Fourteen of the sensitive flowers moved in 12 days ago, trundling their suitcases, swearing their little hearts out and each wondering if they had been the victim of a postmodernist, Chantelle-esque trick in which they were the only real celebrity in the house. But in the past week, they have been dropping like flies.

First Donny, who thought he was Johnny Rotten and may or may not have wet the bed, scaled the perimeter wall. "I'm not fucking waiting on some moron and her family," he pouted, announcing that Donny Tourette (who?) was far too famous to make tea for Jade Goody.

Next, Ken Russell lost it over a plate of cheese and crackers. "Jackiey is a disruptive force verging on pure evil," said the loopy movie legend. He hasn't led a sheltered life, the man who made The Devils, but after a few days of Jade's mum he realised that life on a reality TV show was like living "in a society riddled with evil and hatred", and he couldn't take it any more.

Then on Friday, little Leo Sayer smashed his way out with a shovel handle. Having told Big Brother bosses that they ought to treat celebrities with considerably more respect, he left because he had run out of underpants. "I don't wash my own clothes," he told them. "That's demeaning. It's not good enough."

Jackiey was voted out on Wednesday, and Carole Malone followed on Friday, leaving only nine whingeing housemates arguing about the lemon squash. But didn't celebrities used to be made of sterner stuff than this? Jack Dee didn't walk out of the first Celebrity Big Brother - although he made several dramatic and fruitless attempts at escape, and was punished by being kept in until the very end and voted the winner.

Vanessa Feltz didn't quit either, despite staging a public collapse all over the dining room table. In the third series, it was only under extreme duress that Germaine Greer left the house when her attempts to incite a naked protest failed. And if Ken Russell wants to see what a real disruptive force verging on pure evil looks like, he should try shacking up with a grumpy John McCririck for six fun-filled days.

Leo Sayer's biggest problem, apart from that he can't wash his pants and doesn't know how to give a V-sign, appeared to be that he wasn't being taken seriously enough as A Celebrity. Asked to nominate two people for eviction, he chose Jack Tweedy because he is not properly famous, and Jo O'Meara because she doesn't deserve to be famous at all. "She rides on a bus and buys cheap clothes which she is proud of," he said, horrified, evidently forgetting that earlier he had told Davina McCall that O'Meara was was his favourite housemate. "You have to be current to keep you in the public eye." The day before, he had cheerfully admitted that he hadn't had a hit for 30 years.

Big Brother bosses have refused to speculate about how they might eke out the show for another two weeks with three housemates too few. They won't confirm or deny that other celebrities will be brought in to replace them. But you have to wonder whether there are any more celebrities left. Somewhere in panto land, are the Krankies waiting for a phone to ring? Is there a Blue Peter dog at a loose end? Does David Cameron have the programme makers on redial, desperately hoping that they might let him in to make a mural with Danielle, Shilpa and Cleo?

It is for this reason that Big Brother must exist. The programme has become a celeb factory, churning out C-listers crafted in loving detail and sending them off into the land of "reality" TV. With proper talent like Ken Russell flaking out over the Tuc biscuits, we need programmes like this to make us new slebs. If Jade's mum did not exist, they would have to invent her. And there isn't a pervy old film director in the world who could come up with quite that standard of heroine.