Since his weekend decision not to hold a general election Mr Brown has sought to regain the political initiative with statements on Iraq and on his government's tax and longer-term spending plans.

But those tax plans - on inheritance tax, "non-doms" and green taxes on flights - have prompted accusations from both the Conservatives and Liberal Democrats that their policies have been stolen.

In the Commons, Mr Brown faced a volley of abuse from Mr Cameron, who accused him of lacking courage and "bottle".

'Flunk an election'

The Tory leader mocked the prime minister for denying that he would not have called an election even if the polls showed he would have secured a 100 seat majority.

"Do you expect anyone to believe that?" asked Mr Cameron, who added that Mr Brown's failure to hold a referendum on the EU treaty also "damages your credibility".

"You are the first prime minister in history to flunk an election because you thought you could win it."

He made fun of Mr Brown's book entitled Courage, saying: "Do you realise what a phoney you now look? Have you found a single person who believes your excuses for cancelling the election?"

He pressed the prime minister to say if the draft pre-Budget report that was written before the Conservatives' conference had included plans to cut inheritance tax or on levying non domiciles.

Mr Brown responded that the government had raised the exemption on inheritance tax on 10 occasions since 1997.

He said the Tory leader would have to explain why the Conservatives' plans would only generate £650m rather than the £3.5bn that they claimed.

Name calling

Mr Brown said he would not take lectures from a man who had been for grammar schools, VAT on air fares and museum charges and then went against them.

Mr Cameron said if the prime minister had questions about Tory plans he should "find a bit of courage, get a bit of bottle, get into his car, go down to Buckingham Palace and call that election".

Continued....