Polls have opened in Britain's national election, a contest that is expected to produce an ambiguous result, a period of frantic political horse-trading and a bout of national soul-searching.

Prime Minister David Cameron's Conservatives and Ed Miliband's Labour Party are running neck-and-neck, and neither looks able to win a majority of Parliament's 650 seats.

Many voters are turning elsewhere — chiefly to the separatist Scottish National Party, which will dominate north of the border, and the anti-immigrant U.K. Independence Party. UKIP is third in opinion polls but Britain's electoral system means it can win at most a handful of seats.

If no party wins outright, it may take days or weeks of negotiation to forge a workable government.

Polls are open Thursday from 7 a.m. (0600GMT) until 10 p.m. (2100GMT).