Nick Clegg's Liberal Democrats were today wooed by both Conservatives and Labour seeking their co-operation in forming a government in the wake of a General Election which delivered Britain's first hung Parliament since 1974.

Tory leader David Cameron made what he described as a "big, open and comprehensive" offer to the Liberal Democrats to work with the Tories in a collaborative government.

It was not immediately clear whether this could involve a formal coalition with Lib Dem ministers in a Cameron Cabinet.

As a major carrot to attract Lib Dem support, Mr Cameron offered an all-party committee of inquiry on political and electoral reform to look at the possibility of changing Westminster's first-past-the-post voting system.

But he stopped short of promising the immediate legislation on a referendum on voting reform offered by Prime Minister Gordon Brown less than an hour earlier.