Nick Clegg will today accuse the Tories of being "completely in hock to the City" as he says the party has quadrupled its dependence on funding from the sector since David Cameron became leader.

Figures produced by the Liberal Democrats today show the Tories have raised more than £15m from companies and individuals connected to the City since Cameron was elected leader in 2005.

The party accepted just £3.9m from the City between 2001 and Cameron becoming leader. Half of the City donors were not recorded donors before then.

Ten percent of the Tory candidates in the coming election are bankers or have worked in the sector, compared with 1.5% of the country as a whole.

The Lib Dems also claim that more than half of the Conservatives' outstanding loans from City individuals and businesses were made under David Cameron: £5.3m out of £9.5m.

Between Cameron's election and 2010, a total of £109m in donations was received; donations from the City account for 14% of this. In the four years before his leadership, donations from the City made up less than 6% of the £67m received.

Clegg will claim "the Conservative party will never reform the banks and rebuild our economy because they are completely in hock to the City of London".

He will say: "They are the party of choice for rich bankers, and no wonder when their major tax policy is to give tax breaks to double millionaires. They even have plans to cut taxes for the banks and raise them for solid British manufacturing companies. They will never change Britain for the better because they are only interested in helping people at the top."

He will argue the Lib Dems have the most progressive tax plans. "Only our party has a positive plan to put money back in the pockets of ordinary people, close the unfair loopholes for people at the top and take on the banks so they never again hold a gun to our heads and put ordinary people out of work."