Livingstone: My 2012 bid was to snare billions of pounds for London

Mr Livingstone told a mayoral hustings in London he didn't bid for the 2012 Olympics because he wanted "three weeks of sport". He said the Games, which will cost at least £9.3 billion to stage, were just a means of extracting funding for London.

He told an audience at St Martin-in-the-Fields church in Trafalgar Square: "I didn't bid for the Olympics because I wanted three weeks of sport. I bid for the Olympics because it's the only way to get the billions of pounds out of the Government to develop the East End, to clean the soil, put in the infrastructure and build the housing."

The Mayor's remarks came after he was criticised by Liberal Democrat rival Brian Paddick for claiming that original sums on the Olympics were "guesswork".

Mr Livingstone said: "It wasn't a mistake, Brian. It was exactly how I plotted it to ensnare the Government to put money into an area it has neglected for 30 years.

"I am delighted that there will be billions of pounds from the Government. That was exactly the plan. It has gone absolutely perfectly."

This week an influential group of MPs said it had "little confidence" the £9.3 billion target would not be exceeded. The Public Accounts Committee said the original estimate of just over £4 billion was "entirely unrealistic" and accused ministers of succumbing to " wishful thinking".

Mr Livingstone helped draft the original Olympics budget but has stressed that his main responsibility was for the level of council tax precept to help foot the bill. He stressed again last night that he had capped the amount Londoners would have to pay.

"I gave a guarantee to Londoners they wouldn't pay more than 38p each [a week]. We held to that," he said.

Mr Livingstone's team says that responsibility for drafting the budget was down to Whitehall but stresses it would have cost £200 million to get a fully costed estimate of the final bill - money the bid team did not have.

The Mayor's comments came at a hustings event organised by Christian groups at which the candidates were quizzed on issues of faith. Tory Boris Johnson praised the work of Christian groups in London which he said had been "neglected" by Mr Livingstone. He said: "We have this amazing utensil, the faith-based community, and they deserve every possible support."

Both the Labour and Tory candidates pledged to allow the building of more churches. Mr Paddick agreed, saying there was a " desperate need" for bigger places of worship.