Andrew Grice: Patten should defy his Tory foes and stay as chairman despite

This is the moment we have been waiting for," the Conservative MP smiled with relish. What was he so excited about? Defeating David Cameron in the Commons (again)? Discovering a Labour policy on anything? Finding someone certain to vote in the police commissioner elections?

No, like many of his Tory backbench colleagues, he was celebrating the turmoil engulfing the BBC. Of course, the BBC has given its Tory critics plenty to crow about. The mistakes by its Newsnight programme over Jimmy Savile and Lord McAlpine, right, were inexcusable.

The £450,000 severance pay for George Entwistle, who resigned as BBC director-general after just 54 days, exposed Beeb bosses with heads in the clouds rather than the real world. Surely, Mr Entwistle should give back half of his pay-off.

Despite all that, the gleeful reaction among Conservatives was over the top.

It exposed their obsession that the BBC is a left-wing conspiracy, and their long-standing determination to dismantle the public service broadcaster and abolish the licence fee.

In the Commons on Monday, David Nuttall, MP for Bury North, hoped for what many fellow Tories wish privately: "This latest debacle will bring forward the day when the British public will have the freedom to decide whether to pay to watch the BBC, rather than being forced to pay for it by the criminal law." (For me, the licence fee is good value at £2.80 a week.)

One Tory claim was that Lord McAlpine's treatment would never have been meted out to a senior Labour figure.

This conveniently ignores the fact that the last major BBC crisis blew up when it stood up to Tony Blair over allegations that a dossier on Iraq's weapons was "sexed up".

To make matters worse for the BBC, the Tory attacks are personal. It might have been an asset to have a former Conservative Cabinet minister as chairman of the BBC Trust at such a difficult time, but Chris Patten has many enemies in his own party. Tory folklore has him as the architect of Margaret Thatcher's downfall in 1990, which is unfair.

The then-prime minister, fatally wounded in a leadership challenge by Michael Heseltine, asked her Cabinet ministers individually whether she should soldier on.

Like most, Lord Patten advised her to stand down. Under her successor, John Major, Lord Patten became Tory chairman. As a liberal, pro-European he was hated by the Thatcherites, who accused him of leading the new PM astray on the EU.

One member of the Thatcher praetorian guard who walked away was Lord McAlpine, the Tory treasurer. At a party at his Westminster home on election night in 1992, there were cheers when Lord Patten lost his Bath seat.

Lord McAlpine, now 70 and who has had two major heart operations, has every right to feel aggrieved with the BBC for the disastrous Newsnight report falsely pointing a finger at him as a paedophile. He handled a BBC interview on Thursday with great dignity.

But, given the history of his relationship with Lord Patten, it is no surprise that, like some Tory MPs, he is gunning for his old foe to be ousted from the BBC.

Lord Patten hasn't covered himself with glory in the crisis. "He has looked a bit off the pace," one of his remaining friends at Westminster told me.

But after the loss of the director-general, David Cameron's instincts that he should remain at the BBC helm are surely right.

Lord Patten was a good minister and European Commissioner. He now needs to be a good BBC Trust chairman; ministers are said to detect signs that he knows what needs to be done.

Mr Cameron may not relish another battle with his backbenchers, already on the rampage over Europe and wind farms.

But, as someone who worked in commercial television for seven years at Carlton Communications, the PM should realise better than most politicians the value of the BBC, whatever ITV's grievances about its protected status.

Mr Cameron will also know that the BBC remains a trusted global brand, a jewel in Britain's crown.

Trust now needs to be restored at home, and soon. But there are some hopeful signs. Ironically, the BBC has been at its independent best in the way it has reported its own worst mistakes. Newsnight beat itself up on live TV a week ago, its presenter Eddie Mair asking a commentator whether the programme was "toast."

Mr Entwistle's brief spell in the top job was ended by a John Humphrys interview on BBC Radio 4's Today programme. I have heard several BBC programmes declare: "We asked the BBC for an interview but no one was available."

It's the equivalent of a newspaper splashing a grovelling apology all over the front page rather than burying it inside.

Like those Tory MPs, some newspapers are relishing the BBC turmoil, a useful diversion from the imminent threat from the Leveson report into phone hacking. The papers could learn something from the BBC's exemplary coverage of its own troubles.