A leading member of Britain's third largest political party has met a top civil servant for 'unprecedented talks' and offered to be finance minister if the next general election returns a hung parliament, according to a report Sunday.

Liberal Democrat Vince Cable said he was questioned by Nicholas Macpherson, the finance ministry's permanent secretary, about what his party's demands would be if there were a coalition government after the next election widely expected to be held May 6.

'He wanted to know what we attached priority to. He wanted to know what we felt strongly about,' Cable told the Observer newspaper.

Cable, an ex-Shell chief economist who is thought to be the only leading British politician to have foreseen the 2008-09 financial crisis, is the economic affairs spokesman for the Liberal Democrats, the second largest in opposition after the Conservatives.

Cable said his ideas on tax and spending were well received and told the paper the talks were a sign the ministry was 'taking seriously' the prospect of the Liberal Democrats playing a leading role in economic policy after the next election.

Cable said he would accept any offers to become finance minister, adding: 'I wouldn't be in this business if I wasn't willing to take the responsibility if it was to come my way.'

Electors in Britain rarely return hung parliaments - the last such was in 1974 and the one before that in 1929 - but several opinion polls in recent weeks have pointed to an uncertain verdict at the next election.

Two more polls were thought to back the view Sunday: an ICM-News of the World survey put the Tories six points ahead on 38 percent, while research by YouGov for the Sunday Times suggested the party enjoyed a seven-point advantage.

Cable said he had serious reservations about working with either Labour or the Conservatives but the Observer said he was 'noticeably more critical' of the Conservatives' response to the financial crisis than of ruling Labour's.