Only two months after the show's host, David Dimbleby, 60, accused BBC1 of "dumbing down", his own programme was charged with heading the same way.
Pete Townshend, Sting and Peter Gabriel are all also being courted by producers planning September's series. While lightweight Liz Hurley could even take her place on the revered panel if she could prove sufficient political knowledge.
Editor Charlie Courtauld vociferously denied that he was turning the heavyweight political programme into a celebrity showcase.
"There is no way that we are going to turn this programme into the David Dimbleby chat show. I am not inviting celebrities just because I want to meet famous people."
He insisted that moves to broaden the spectrum of guests would keep politicians on their toes. "We know what the politicians will say and they know each other's responses. But they don't know how Janet Street-Porter or Billy Bragg are going to react," he said.
One senior Conservative politician, who did not want to be named, was scathing about the idea. "I would not appear on that programme, they have no knowledge of parliamentary affairs. It would just turn into lots of celebrities arguing with each other," he said.
Labour's Tony Benn was less critical but fearful that it was symptomatic of a greater decline in parliamentary discussion. "Political debate is being destroyed in Britain and it is quite a serious problem.
"We very, very rarely see serious political discussion. I quite enjoy appearing on the programme when I am asked and I would not want to be unkind to it but it would cease to be a political discussion if it brought in too many people who did not understand the subject."
Mr Courtauld is adamant that his vetting process would weed out any political lightweights. The show has already widened its list of guests with recent appearances by such well-known faces as broadcaster Janet Street-Porter, singer Paul Heaton and comics Jim Davidson and Norman Pace.
The editor described Miss Street-Porter as his "ultimate guest". "People were expecting anodyne chat by someone who didn't say anything very interesting. In fact, her contribution was stimulating, interesting and surprising - surprising being the most important."
He denied rumours that Liz Hurley was likely to appear but insisted that nobody, even Hugh Grant's girlfriend, would be discounted if they could prove a strong understanding of politics and the ability to discuss it for an hour under pressure.
Some stars have already balked at the prospect of facing such an inquisitive audience. Jeremy Clarkson and Chris Evans have both turned down the chance to appear, much to the "surprise" of the editor, he said.
Independent production company Mentorn Barraclough took over the contract for the flagship political show at the beginning of the current run and has injected what Mr Courtauld calls a "good dose of reality".
He added: "We have increased the panel from four to five and we have been able to bring in celebrities, trade unionists and representatives from all faiths.
"Although politicians are still the backbone of the show, having a good mix of panellists ensures the discussions are less predictable."