That was the week that was - and the Westminster hothouse was certainly set all agog.

On Wednesday the Commons passed the 42 days clause in the Prevention of Terrorism Bill by just nine votes - the number of Northern Irelanders from Dr Paisley's party who were, according to reports, "persuaded" by promises of more than £1billion of extra spending in their province.

Then on Thursday the place fell about with astonishment when the Tories' Shadow Home Secretary David Davis said he was resigning to fight a by-election in his rural and suburban East Yorkshire seat.

Is this his moment of madness or a courageous and principled act?

The dividing line between heroic leadership and looking like a complete prat can be pretty thin, and for Mr Davis the jury is out.

Most people in the hothouse, politicians and press alike, think that it's madness. The view outside may be different.

My own fear was that with Liberals and Labour not standing it could be an open goal for right-wing headbangers in UKIP or (worse) the BNP.

But they have both said they won't stand, for which I am puzzled but pleased.

Former Sun editor Kelvin MacKenzie backed by the Murdoch press could be a different matter and a serious challenge.

He might also be able to move the argument away from the one-issue campaign on civil liberties that Mr Davis wants.

The other bombshell of the week, the vote in the Irish referendum on the Lisbon Treaty to reform the European Union, could help him to do that.

The same day that the Commons passed 42 days, the Lords voted by 280 to 218 (a huge vote by House of Lords standards) to reject having a referendum on the treaty.

I was one of 63 Liberal Democrats who made the difference by voting with the government.

The Conservatives pulled out all the stops (including a lot of old folk I did not recognise!) but there were also some well-known Tory Lords who voted against a referendum, including Michael Heseltine, Douglas Hurd and Leon Brittan.

Then came the Irish vote.

Where does it all go now? The truth is that no one knows and the European Union is in crisis, which is good for none of us.