Ken 'trailing Boris' in London Mayor race

Mayor of London Ken Livingstone is seeking to get his re-election bid back on track after a bruising few months.

The launch of his campaign on Tuesday to hold on to the keys to City Hall comes as a poll finds him trailing Tory challenger Boris Johnson by 12 points.

The YouGov survey for the Evening Standard put Mr Johnson on 49%, Mr Livingstone on 37% and Liberal Democrat candidate Brian Paddick on 12%.

Mr Livingstone has withstood a stream of allegations recently which resulted in the resignation of his race advisor, Lee Jasper, earlier this month.

The Electoral Commission is also now considering a complaint that the Mayor has failed to declare any donations to his campaign.

But Mr Livingstone's office hit back at the Tory MP who referred the matter to the elections watchdog and accused Mr Johnson's campaign of trying to divert attention from the real issues of the campaign.

"These arrangements have been checked with the Electoral Commission as being entirely appropriate," a spokesperson insisted.

"Fundraising is not done by Ken Livingstone personally. He is not registered as a receiver of donations. This has been checked and approved by the Electoral Commission."

On Monday, Mr Johnson pledged to help struggling Londoners take a first step onto the housing ladder.

The Tory hopeful promised to build 50,000 more affordable homes by 2011 and renovate 84,205 empty properties to help low-income Londoners off waiting lists.