Conservative party

The survey taken at polling stations across the UK suggests the party could get 314 MPs when all the votes have been counted after Thursday's poll.

Labour would get 266, the Lib Dems 14, UKIP none and the SNP 34, the NOP/Ipsos MORI poll for BBC/ITV/Sky suggests.

The pound fell sharply in value after the exit poll was published.

Early results are suggesting a swing to Labour - but it is too early to say whether the exit poll is accurate.

Home Secretary Theresa May, the U.K.'s interior minister, told an audience at the Conservative Party conference that Britain should tighten control of its borders, admitting vulnerable refugees but keeping out those who simply want a better life.

She said other European countries should also toughen up their border controls, arguing that in the last few years more people had applied for asylum in the EU from Balkan countries — which have not seen war for years — than from war-torn Syria.

Analysts say the election is a toss-up and Harper faces an uphill battle to form another majority government. If Harper wins he would become the first prime minister since 1908 to win four consecutive elections.

The prime minister dissolved Parliament Sunday in a visit to the governor-general, who serves as Canada's formal but mostly ceremonial head of state.