Leading City figures are resuming donations to the Tories, it is reported.

Shadow chancellor Oliver Letwin said the cash was a "clear sign of disillusionment with the government and of the growing credibility of the Conservative Party".

Interviewed in the Telegraph, party chairman Liam Fox said: "We've been doing dummy runs already. I'll ring up a constituency and tell them the general election is next week, then send in a crack team to see how they are coping."

Meanwhile, apparently seeking to retain Labour's ties with business, chancellor Gordon Brown will this week open Lehman Brothers' new European headquarters in Canary Wharf.