Election spending

Conservatives: �12.8m Labour: �11.1m Lib Dems: �1.4m

The figures have been released by the Electoral Commission as part of new rules forcing political parties for the first time to show how much they spent on their campaigns.

Advertising was the biggest cost for all three main political parties in a campaign which included Labour's depiction of William Hague with Margaret Thatcher's hairstyle.

The Tories, whose campaign included pictures of children turning to crime while classrooms lay empty, spent nearly �4.5m on adverts, a total topped by Labour's �5m.

This poster of Hague was part of Labour's campaign

William Hague's frenetic helicopter journeys across the UK were part of a �1.5m Tory transport bill, eclipsing the �786,000 spent by Labour and the Lib Dems' �673,000.

Mail shots were another big campaign price tag for the two largest parties, as was sending unsolicited material to voters.

The Electoral Commission figures also show the UK Independence Party spent �749,000 on its campaign, and public sector Unison also forked out �775,000 in the pre-poll push.

Costs for the Scottish National Party's campaign have yet to be unveiled because the SNP failed to meet the six-month deadline for submitting figures.

A party spokesman blamed an "administrative delay" and, pledging to lodge the figures shortly, said the SNP had "nothing to hide".