The Sketch: Who would die in a ditch with Patricia Hewitt?

But what on earth were they up to? What did they think they were doing? It's marvellous how bad politicians are at this sort of thing. They couldn't organise an act of congress on a porn set.

How many plots to remove the Prime Minister have we had in the last two years? How many ultimata, last chances, final demands for improvement? But he's still in place, he's still there. He looks like he's been dead for three days but there he stands, bellowing away at us, roaring and boring, the Tories are wrong, wrong, wrong. "They have no policy whatsoever!"

Some say he was doing well at PMQs. He had that joke about the Tory marriage policy changing through the day. He'd let Cameron make a couple of comic sallies and then said, "He can't say I do or I don't." Labour cheered and yes, many of us laughed (the essence of humour is surprise, so we always laugh when Brown makes a joke). No, it would have been something of a win for the PM, except the BlackBerries were buzzing all round the chamber with news of a leadership challenge being mounted.

Another one! But how? And more important, who? It's the most important question in these affairs: who else is in? Do you want to be associated with these people at this stage in your career? And "the people" will be determined by the Big Who at the bottom of the letter.

That name I heard as "Huhne". Chris Huhne? Oo, I don't know, will that work? "No, Hoon." Don't be ridiculous, are you mad? Who would rally to Geoff Hoon's flag? Who would die in a ditch with Patricia Hewitt? And who wants to tear their party to pieces in the run-up to a general election?

But it was worse than that. The plot had an even more overwhelming flaw. There was no plot.

By mid-afternoon the prominent Brown-basher Barry Sheerman, for instance, hadn't received anything. He didn't know what was in the letter. "How many signatories will you get?" I asked him. "Oh, 150? But 100 would do it." "You'll get 30," I said. He offered his hand for a bet. We settled on a tenner.

We'll both lose because they won't get any signatures at all – the email doesn't ask for signatures. "It doesn't ask for anything," Mark Fisher said. "It's a fatuous letter produced by Geoff Hoon's vanity, talking about the need for clarity and unity. It's laughable to think this is an effort to unite the party. The effect would be to split it. There's no appetite for it, we're committed to Brown, the decision was made two years ago when all those people in corners didn't make it work."

Keith Vaz couldn't see any more than 30 supporters of the proposition coming forward. "There would have been more last year," he said.

Still, it kept Lindsay Hoyle laughing. It had absolutely no chance of success because there was no alternative candidate putting their head or hand up. "Anyone-but-Brown still needs a Somebody," was his line. And all there is are nobodies.

Actually, I had a candidacy. The Milibands. But both of them, like the twin brothers that run Poland. The Labour Party is too diverse for any single person to hold it together. Hoyle put his finger on the flaw in this scheme. "They've only got one banana."

But, I asked every Labour MP I came across, what were they up to, Hoon and Hewitt? Hmm, Hoon wanted to be that EU trade commissioner, a number of backbenchers pointed out. As did Patricia Hewitt. The mention of her name never went over well. "She's making a fortune in private enterprise, she's virtually left Parliament, but she thinks she can come back and tell us what to do!" Yes, that's galling, I suppose.

It was so ineffectual, so purposeless, so ill-thought-out, so lacking in support that it was hard to believe that Charles Clarke wasn't involved.

What a wet, spat-upon squib it was. Said Andrew Mackinlay: "They make Guy Fawkes look successful."