The real reason for David Davis' resignation

No, I have absolutely no idea what he's playing at.

I can however report that the universal reaction at Westminster when the news broke was that it must be David "TC" Davies, the newish MP for Monmouth, who is widely regarded as being more than a little loopy. (The one with the Land of Hope and Glory ringtone). In fact I was at a reception at No. 10 last night, talking to Hamish Sandison, who is standing against TC in Monmouth at the next election. Hamish manages to pull off the admirable feat of being a very English-sounding barrister with a very Scottish name who lives in Wales: in Monmouth, in fact. He was telling me it was pure joy standing against TC because he does and says so many mad things.

Anyway, it turns out not to be TC but his rather more famous namesake. "Without an e" as he's known. (Speaking of which, who can forget his leadership campaign, with the two young women in extra tight "It's DD for me" T-shirts?). My suspicions and opinions at this stage are as follows:

- Either David Cameron is in on the whole thing, but the plan is to distance himself from it, just in case it backfires; or DD has forced David Cameron into it, which is a totally bizarre state of affairs. Nick Robinson has just said on BBC News that Cameron's description of it as "a courageous personal decision" is code for "bonkers".

- I don't think the fact that the Lib Dems have been squared off, and agreed not to stand in a by-election they could potentially win, is a good move on their part - I thought their line was that they were the true defenders of civil liberties, and the Tories were only playing party politics on these issues? Seems weird to cede the ground of defender of civil liberties to David Davis of all people. If they'd refused to take part because it's all an ego-driven stunt, then I'd entirely endorse that - I'm leaning towards the view that Labour should do that too. Why play his games?

- The result of any by-election will be completely irrelevant to the 42 days question. Opinion polls show that a majority of the public are in favour of 42 days, with appropriate safeguards. I would imagine that in a safe(ish) Tory seat, there would be an even bigger majority in favour. DD faces a real danger that Tory voters in his seat won't see the point of turning out - or could even vote UKIP or BNP in protest. If he gets re-elected it will probably be with a greater percentage majority, as the Lib Dems aren't standing, but with a greatly reduced turnout. What does that prove?

- And on a cautionary note, I would just say one word - Winchester.