LONDON, June 8 (Xinhua) -- Early risers and people on their way to work were among the first to cast their votes Thursday in what has been described as Britain's most crucial election for decades.

Although Theresa May is on target to hold on to power, a late rally by Labour leader Jeremy Corbyn may thwart the Conservative's ambition to give their majority a turbo-boost.

When May called the snap general election just six weeks ago, she held a working majority in the British House of Commons of just 17 seats.

She has pleaded with the British public to increase her strength in parliament to enable her to fight for a good deal with Brussels when negotiations start later this month on Britain's withdrawal from the European Union.

The battle for 10 Downing Street has emerged as a two-horse race between May and Corbyn, with political commentators saying the May landslide predicted just weeks ago is now less likely.

The election result is crucial as it will set the tone for those all-important talks about the future EU-UK relationship.

May wants to strike a deal she described as "good for Britain", while Corbyn says he respected the majority decision by Britain to quit the EU, but he wants to maintain access for business and the protection of workers' rights.

Hundreds of polling stations across England, Scotland, Wales and Northern Ireland opened at 7 a.m. local time (0600 GMT), and close at 10 p.m.

Almost 47 million people, aged 18 and over, a record number, are entitled to vote in the election, half a million more than in the 2015 election.

Polling stations have been set up in a whole range of premises, from libraries to schools, with more unusual venues such as public bars, supermarkets, hairdressing salons

The kitchen of one house in Yorkshire will act as one of the country's smallest polling stations. Peter Easterby, 63, and his wife Liz, 53, expect a procession of around 40 neighbors to make the journey to vote in their remote home in Driffield, 48 km east of York.

Traditionally campaigning does not take place on voting day, with cabinet ministers and opposition shadow ministers making the journeys to their respective constituencies to await the results.

As well as being prime minister and resident of 10 Downing Street, May is also a constituency MP, so she will head to Maidenhead in Berkshire, a seat she has represented since 1997, to await her fate. If she failed to win she would immediately cease to the prime minister.

Her constituency includes Windsor Castle, one of the official residences of Queen Elizabeth II. The Queen, however, does not vote so nobody will ever know who she would support.

At precisely 22:00 local time, the voting stops, the pencils used to place crosses on ballot papers will be stacked away, and an army of vote counters take over.

Over the following hours, the results will flow in from the 650 parliamentary constituencies, each choosing one MP to represent them in the House of Commons. The first party to hit 326 seats will win the election.