Boris: I'll cut costs to get London through crisis

The Mayor will stress he does not want to add to the financial pressures endured by many families struggling to cope with the rising cost of living.

He announced plans earlier this month to freeze the Mayor's share of the council tax next year. But he claims to remain committed to his "wider ambitions" such as delivering a successful Olympics in 2012.

Mr Johnson has been under pressure to reveal how he plans to use his powers to get through the crisis.

He angered many Londoners this week by defending wealthy bankers and telling them to "stop whingeing" about house prices boosted by City bonuses.

A City Hall source said the Mayor would tell the conference: "In tough economic times we mustn't add to people's burdens. Labour have got us into this mess and we've got to get out of it.

"Although overall we don't want to add financial pressures we must not lose sight of wider ambitions - we're still going to have a fantastic Olympics, for example."

The cost-saving plans came as Mr Cameron, who has just taken up jogging, refused to rule out health taxes - targeting unhealthy foods, alcopops and high-strength beers - to encourage-responsible behaviour under a Tory government.

But he added: "We have to be careful, particularly at a time like this when family budgets are so squeezed."

Mr Cameron will seek to bring a touch of Barack Obama's star quality to the conference in Birmingham by copying his "plan for change" campaign slogan.

Its use underlines how his team is modelling his strategy on Mr Obama's bid for the White House.

He is also following Senator Obama's formula for handling questions about his relative inexperience.

The Democrat responds by saying the type of experience held by the Republicans is not what the US needs.

Asked in an interview with Sky News to be broadcast tonight about the Prime Minister's "novice" remarks, Mr Cameron said: "Yes, this Prime Minister has got experience; he has got the experience of building up the biggest budget deficit of any industrialised country, he has got the experience of designing the regulatory system that failed to prevent the first run on a bank in Britain in 150 years.

"He has got the experience of saying year after year 'I have ended boom and bust'. And yet now we face really difficult economic circumstances.

"Now, I don't think that is the experience we need right now."

The Tory leader will hold an emergency debate, featuring shadow chancellor George Osborne, on the economic crisis.