But I hadn't counted on the tenacity of Labour, who are trying to spin this story as far as it will go. They've had some of their biggest hitters doing the media rounds – including Jack Straw and Peter Mandelson, whose request for a watchdog investigation into Ashcroft has been turned down. The Business Secretary has since come out snarling, saying to Sky News this morning:
This is a dangerous route for Labour to go down, on many levels. Not only (as Guido points out) is Mandelson not really the best poster boy for clean politics, but it risks drawing more attention to Labour's own non-dom donors, and suggests that Brown & Co. aren't just "getting on with the job" of government. With the election only weeks away, maybe they should create the impression that they've got better things to do.“
"All these years he's been dodging what he should have paid in tax in full ... instead he's chosen to give all the money to the Conservative party. Perhaps they'd like to pay it back now?"
UPDATE: Paul Waugh's put up a blog post wich suggests that Mandelson isn't going to get very far with this, and that Ashcroft was telling the truth yesterday when he said he hadn't gone back on an undertaking.
UPDATE 2: Labour have just released this attack ad: