SNP Commons ambush on Glasgow by-election.

Just back from the Press gallery where we watched the SNP ambush the government in the Commons by attempting to move the writ for the Glasgow North East by election.

Dundee East MP Stewart Hosie stood to move the writ but Nick Brown, Labour's chief whip, rose to object. Looks like Labour had a last minute tip-off, just as we did.

That means the writ goes to a debate and a vote at 3.30pm. The Labour whips are sure they can win the vote, even though lots of MPs, on both sides, are in Norwich North for the last two days of campaigning.

(Reports from there that the Labour candidate in Norwich North has come down with swine flu - for him the war is over.)

We'll have to rush downstairs again for this debate, just as the government is, I'm sure, scrambling as many MPs back into the chamber as it can.

We can expect the SNP to talk about the double standard of a by-election in Norwich while voters in Glasgow go unrepresented while jobs are lost at Diageo and a controversial schools closure plan goes through the local council.

The SNP might not win the vote but they claim the moral high ground and get the headlines tomorrow.