Londoners' council tax is expected to raise �650m for the Games

They are expected to ask Mayor Ken Livingstone to ensure guarantees are built into the Olympic Bill during a questions session at City Hall.

Conservative assembly member Angie Bray said the government should "put its hand in the nation's pocket".

Mr Livingstone said their call was "the same old scaremongering".

'Professional doom-mongers'

Ms Bray told BBC News: "It cannot be just Londoners and the Lottery that are funding the Olympic Games.

"We are absolutely thrilled that we have won them but it's a games for the whole of the country that just happens to be staged in the capital."

Mr Livingstone criticised the assembly members calling them professional doom-mongers.

"Why are the Conservatives on the London Assembly the only ones who will not get behind the fantastic opportunities for London in hosting the 2012 Games," he said.

About �650m will be raised from council tax in London and another �250m from the London Development Agency.

A further �1.5bn will be raised by the Lottery, while similar sums will be raised from ticket sales, marketing, sponsorship and television rights.