"Hasn't the chancellor failed to make the hard choices that would allow the full 1% cut in interest rates that this country needs?" he asked.

Mr Hague said Gordon Brown's pre-budget report was "a massive missed opportunity to reverse the blunders of the past 18 months and do something to save people's jobs".

William Hague: On the offensive

Throwing a piece of paper across the despatch box, the Tory leader demanded to know the prime minister's response to an Economist survey placing the UK at the bottom of a growth league table for next year.

Mr Blair denied this, saying: "All the forecasts actually put us ahead in this year and ahead in the future too.

"The single most important thing we can do is hold firm to the course of economic stability."

The Liberal Democrat leader Paddy Ashdown choose to attack the prime minister on the apparently mixed messages from the government on the euro.

Mr Ashdown said: "Let me remind him one of his cabinet ministers has said 'if' and another has said 'when' - they cannot both be right."

But Mr Blair insist this could be the case and that Trade Secretary Peter Mandelson and cabinet "enforcer" Jack Cunningham had not contradicted each other on when Britain might join the single currency.

He said: "To join the circumstances must be right: those are that the economic benefits are clear and unambiguous."

When he returned to the despatch box, Mr Hague asked the prime minister for the yes of no answer he had been promised last week on whether the government would hold a referendum on proportional representation this parliament.

Mr Blair said he had "always envisaged" holding the referendum before the election and this "remained an option".

To Mr Hague this meant the prime minister could not "tell the difference between yes and no".

But Mr Blair countered by accusing the Conservatives of blocking all constitutional reform. "I'm more open," he added.

Mr Hague described the Jenkins proposals for an AV Top-Up voting system as a "complete dog's breakfast".