Cameron: Budget within 50 days if Tories win

Mr Cameron confirmed a budget would be needed to introduce cuts to corporation tax and allow new businesses to start up without paying national insurance on their first 10 employees.

He said: "These are the things that will get the economy moving. I think people need to see that action is being taken and action is being taken early."

The Conservative leader also claimed the UK's fiscal deficit needs to be slashed to stimulate economic growth.

He said: "We do believe that to get the economy moving you've got to lift the black cloud of deficit away. That is what is chiefly, we believe, holding us back.

"We have a serious plan. We've been absolutely clear we have to make a start on this work in 2010 and get rid of the bulk of the structural deficit within parliament.

"Protecting the UK's triple A rating is central to our plans."

Mr Cameron was also quizzed about the the tax status of his party's deputy chairman Lord Ashcroft.

Lord Ashcroft is one of the Conservative's biggest donors, having pumped millions of pounds into party coffers, and sits in the House of Lords despite admitting yesterday that he pays no tax in the UK.

But Mr Cameron told journalists they were "flogging a dead horse" when it came to asking him how long he had known Lord Ashcroft had been registered as a non-domicile for tax purposes.

Mr Cameron said: "People want to know what his tax status is. People now know what his tax status is.

"I admire people who try to flog a dead horse. But the horse is dead and should no longer be flogged."

Mr Cameron was joined at Reuters by shadow Chancellor George Osborne and shadow business secretary Ken Clarke.

Mr Clarke backed Mr Cameron's argument that the finance deficit needed to be cut, and warned that victory for Labour in the forthcoming election would weaken the pound.

He said: "If investors don't believe that a newly elected government has the political will to deal with the deficit and pay down debt, they will demand much higher interest rates before they lend us any money.

"As we watch the cost of borrowing soar and the pound fall we can see clearly we are still in a crisis."