Cameron condemns 'bashing' tactics

The Tory leader insisted he would not seek "cheap headlines" by blaming greedy City practices for the current crisis.

But speaking as it emerged that Bradford & Bingley was set to be taken into public ownership, he also warned that the Tories would not sign "blank cheques" for the taxpayer to bail out failing institutions.

"What you won't hear from me this week is the sort of easy cheap lines beating up on the market system, bashing financiers," he told BBC1's Andrew Marr Show.

"It might get you some easy headlines, but it is not going to pay a single mortgage, it's not going to save a single job."

Mr Cameron denied he was steering clear of criticising bankers and hedge fund managers because they contributed heavily to Tory coffers.

"They don't have any influence on my policy at all," he said.

He said there had been "failure of regulation" in the financial sector, and the Government had been wasting time rather than reforming the system.

"I think that we have had a failure of regulation and we have had a debt boom that went on for far too long and it reached into parts of the economy it shouldn't have done. The whole thing has become infected and it has got to be dealt with."

Mr Cameron stressed that the Opposition would act "responsibly" and help the Government deal with the crisis. But he said nationalising institutions such as B&B and Northern Rock left the taxpayer with the "whole risk".