Just watch that Gove bandwagon gather speed ...

Wasn't that nice Mr Obama a sweetie, the way he tried to help our Dave end the war in the Tory party while he was over in Washington this week?

Mind you, given how little the President has managed to do to end the war in Syria, I don't much rate his chances with the fundamentalist rebels of the Conservative party. Never mind, I still think it was jolly nice of him to try.

The truth, though, is that the coalition is crumbling. No, not the Tory-Lib Dem coalition -- that's in fine fettle compared to the one I'm thinking of: the ramshackle, increasingly dysfunctional bunch of lemmings we know and love as the Conservative party.

In the words of Benedict Brogan, deputy editor of the Daily Telegraph (yes, the paper better known as the Torygraph), writing on his blog on Tuesday: "The Tories look like a bunch of self-indulgent lunatics."

President Obama tip-toed through the Tory euro-minefield with considerable skill, I thought -- it does make some sense, he suggested, to seek to mend a relationship before breaking it off. And that, of course, is pretty much what Mr Cameron says he wants to do with the EU: renegotiate, and then call the referendum.

There's a problem, though. When one party in a relationship threatens week after week, year after year: "Unless you change the way you behave, I'm not going to be able to carry on like this," there is a real chance that one day the inevitable reply will be: "Fine, perhaps you'd better move out."

But if David Cameron's poll ratings are sliding down the plug-hole, it's not because voters disagree with him about exactly when to hold that wretched referendum. It's because he's looking increasingly like a weak prime minister unable to control his own party, an old Etonian toff who's no longer even capable of organising cocktails and canapés in a Notting Hill nosherie.

It's as if Tory MPs have clean forgotten what they were told back in 2006 to explain why they hadn't won any elections for a decade. "Instead of talking about the things that most people care about, we talked about what we cared about most. While parents worried about childcare, getting the kids to school, balancing work and family life, we were banging on about Europe." The man who told it to them straight? Er, their party leader, a certain D Cameron.

We've been here before, of course. John Major went through exactly the same agonies, facing exactly the same euro-obsessives, and we know what happened to him. This time, though, unlike in 1997, it may not be Labour who reap the benefit -- Ed Miliband hasn't got quite the same effortless TV appeal that Tony Blair mastered so skillfully -- so it may well be Nigel Farage and UKIP who stand to gain the most.

When the prime minister unveiled his "in-out referendum" strategy last January, I wrote: "There is a strong possibility that David Cameron, in one single, ill-considered, badly-timed and unnecessary speech, may have sown the seeds of his own downfall."

My argument then was that all of the likely election outcomes in 2015, the least likely was an overall Tory victory that would enable him to remain in Downing Street. Now, though, I'm beginning to think his downfall could come even sooner.

It goes like this: the UKIP bandwagon and the Tory rebellions continue to roll. At the European parliament elections next year, the UKippers may even get more votes nationwide than the Tories. (Remember, turn-out for the euro-elections in 2009 was a dismal 34.7 per cent.) Tory MPs go into full-blown panic mode, just 12 months ahead of the general election.

The cry goes up: We can't win with Cameron. (After all, if they could unceremoniously dump Margaret Thatcher in 1990 because they thought she was going to lose them the next election, I don't imagine they'll have too much trouble jettisoning Mr Cameron.)

And if you think I'm being fanciful: consider this -- the two Cabinet ministers who so unhelpfully put their heads above the parapet last weekend to venture that they would vote No in a referendum if one were held now, just happen to be two of the ministers with the shortest odds in the betting shop to be the party's next leader. Yes, take a bow, Michael Gove and Philip Hammond.

You may also like to consider this piece in this morning's Telegraph: "Michael Gove has said he wants to be 'the heir to Blair' amid renewed speculation that he could succeed David Cameron as Conservative leader."

If I were a betting man, I'd put £100 on Gove for Tory leader before the next election. There again, it may all look different after the summer.

By the way, don't you think the two Tory MPs who created so much misery for the prime minister this week, with their EU referendum amendment ahead of the Queen's Speech vote, Peter Bone and John Baron, should set up a pub together? "I want a quick chat about Europe -- how about a pint with Farage down the Bone and Baron?"