British voters went to the polls on Thursday morning as up to 50,000 polling stations across the country opened in the most tightly contested general election in decades.

Polling stations are open from 7 a.m. local time (0600 GMT) to 10 p.m. (2100 GMT) on Thursday. The Local Government Association said 627 of the 650 parliament constituencies would start counting overnight, with about 20 not due to begin the process until after 0900 GMT on Friday.

Over 44 million voters are registered to elect 650 members of parliament from 650 constituencies, but voting in the election will take place in 649 constituencies as polling in Thirsk and Malton has been postponed to May 27 following the death of Independence Party candidate John Boakes.

Conservative Party leader David Cameron was the first to cast his vote in his constituency of Witney in Oxfordshire. Prime Minister Gordon Brown, also leader of the Labor Party and Liberal Democrat Party leader Nick Clegg went to their local polling stations later.

The Conservatives have bought the home page advertising slot on YouTube to run a video compilation of Cameron's speeches during voting hours while Brown has sent an email to supporters urging them to encouraging people to vote Labor.

Independence Party candidate Nigel Farage, who is standing in the general election in Buckingham, has been injured in a plane crash this morning and sent to hospital.

The new parliament will be summoned to meet on May 18, when the first business will be the election of the speaker and the swearing-in of members.

A YouGov survey said compared with voting intentions in 2005 the Conservatives had added 2 percent to their support, while Labor had lost eight points and the Lib Dems had gained five.

But the final opinion polls before the general election showed that Britain is heading for a hung parliament although the Conservatives are still ahead during the three-horse race.