Conservatives have branded Ken Livingstone a "credit card mayor" over his plans to borrow £2.5 billion over the next five years.

Details of the London mayor's spending plans are to be revealed later this week, after a public consultation on the issue.

Speaking on Monday, mayoral candidate Steve Norris argued that council tax bills have doubled since Livingstone was elected in 2000.

"Londoners are already paying hundreds of pounds in council tax to City Hall, just to live in the most violent city in the country," he said.

"Livingstone has spent the past four years frittering away millions on pointless political gestures and self-publicity.

"Now the Labour government is giving him a new 'credit card' with a £2.5 billion limit - the trouble is it's London's council taxpayers who will pay the bill."

Norris highlighted how the current budget is being spent in the capital.  Examples included the employment of 19 press officers at a cost of £1.5 million, £2 million on The Londoner, a new newspaper, and £270,000 on new desks and equipment for City Hall.

"If this is how Livingstone spends £25 million, imagine what he would do with 100 times that amount," he added.

His comments were endorsed by Conservative Party leader Michael Howard.

"Ken Livingstone has just granted himself the power to borrow an enormous sum of money, £2.5 billion, that's two thousand, five hundred, million pound loan that he wants someone else, that is, Londoners, to pay back," he said.

"This is the mayor who, in the past four years, has wasted money in the most incredible ways you could imagine.  And now he wants to grant himself a two thousand, five hundred, million pound loan that he wants someone else, that is, Londoners, to pay back.

"The buy now, pay later chancellor has spawned a credit card mayor.  And it's the people of London who are going to pay the price.  So my message to Londoners when voting on June 10 is this: If Ken Livingstone stays, you'll pay.  And there is only one alternative - Steve Norris."