Gordon Brown’s political obituary has been written many times over the 22 months of his short premiership. This time, though, my political antenna tells me that he is in real trouble. And that spells bad news for the Tories. It has been a humiliating week for the Prime Minister. It started with the ridiculous YouTube video in which he seemed to be obeying orders to randomly smile during his three minute monologue on MPs’ expenses. He then travelled to Pakistan only to be snubbed by the country’s President. Next stop was Poland, where the Polish PM lectured him about his “ridiculous” levels of borrowing. Back home he suffered an embarrassing defeat at the hands of Nick Clegg and the Gurkhas and a day later had to back down over parliamentary expenses in order to avoid a second Commons defeat in two days.

Political commentators are apt to use the phrase “It was the Prime Minister’s worst week ever” rather too often to be taken seriously. Yet on this occasion it is warranted. Labour MPs are wandering around the Commons in a state of despair. Those with marginal seats are already planning for their post parliamentary careers. Leadership speculation is starting again, with David Blunkett telling Gordon Brown he has lost touch with voters. The LabourHome website is speculating furiously about a stalking horse about to put his head above the parapet and openly challenge the Prime Minister. Most people assume the MP being talked about is none other than Norfolk’s very own Charles Clarke. He would no doubt reject the ‘stalking horse’ epithet and consider himself to be a serious challenger. And in many ways he is, but his trouble would be raising the number of signatures of his colleagues to get on the ballot paper.

No, there are only two ways for Gordon Brown to go. One is voluntarily, and the other is for seven or eight Cabinet Ministers to tell him the game is up and if he doesn’t quit they will resign from the Cabinet. This won’t happen yet. But following the County Council and Euro elections on June 4th, I can envisage a scenario in which it does.

One Labour MP said privately this week that Gordon Brown was hating the job as Prime Minister. That wouldn’t surprise me. Often when you get something you have waited for it doesn’t turn out to be as good as you had expected.

I must admit that if I were Charles Clarke I would be thinking very carefully indeed about how I played this. In a post-Brown scenario Charles Clarke could indeed have a very important role to play. He is a big beast of the political jungle, and if there is a lot of broken crockery to pick up Charles Clarke should be seen as the man to put it back together again, not as the man to have broken it in the first place. If the latter happens, he will not easily be forgiven by some of his parliamentary colleagues.

So why would Brown’s departure be bad for the Tories? Because they see him as their greatest electoral asset and are very keen that he should not be fatally wounded. Their saving grace is that there is no readily available heir apparent who would be more electorally popular. Alan Johnson is the only Labour politician who strikes just a shard of fear into Tory hearts, but it is highly unlikely he could be persuaded to do the job. Most Tories, of course, pray for Harriet Harman to be the Labour Party’s chosen one. Every Tory Christmas would have come at once. But the big beast lurking in the background is Jack Straw, that great survivor of regime change. Having seamlessly transferred his loyalties from Tony Blair to become Gordon Brown’s leadership campaign manager, Straw is being touted by many commentators as the ultimate ‘man in a grey suit’ who would lead the delegation to tell Gordon Brown that the game is up. Straw, however, may care to think about Michael Heseltine’s* dictum that “he who wields the knife never wears the crown”.

And who said politics was boring?

*UPDATE: Of course, that is not strictly true. Margaret Thatcher and Paul Keating tend to lend weight to the opposite viewpoint.