Polls open in Britain's general election

Millions of people across Britain voted today in one of the most contested general elections between Prime Minister Theresa May and Opposition leader Jeremy Corbyn being held under tight security after two deadly terror attacks by Islamists killed 30 people.

Voting was under way at more than 40,000 polling stations across the country. A total of 650 MPs will be elected. About 46.9 million people, including an estimated 1.5 million Indian-origin voters are registered to vote.

To form a majority in the House of Commons, one party must win 326 seats. Polls close at 10 pm UK time (2.30 am IST).

May, 60, called the election three years earlier than scheduled ahead of what are expected to be tough negotiations with the European Union over Britain's exit from the 28member-bloc.

Britain last voted in a general election in 2015, when then Prime Minister David Cameron won a majority with 331 MPs for the Conservative party. Since then the referendum on Britain's membership of the European Union (EU) in June 2016 has meant a very different political landscape.

Brexit led to Cameron's resignation last year and May's selection by the Tories as their leader.

The ongoing voting is the fourth major UK poll in three years, following the 2014 Scottish independence referendum, the 2015 general election, and the 2016 Brexit vote.

Police have increased security at polling stations, including patrols by armed officers in some areas, following the recent terror attacks.

A spokesperson for the UK's National Counter Terrorism Policing headquarters has said security around polling stations is "constantly reviewed and updated by local police forces".

There were two major terror attacks during the election campaign – a suicide bombing in Manchester on May 22 that claimed 22 lives and an attack by three terrorists who drove into pedestrians and then went on a stabbing spree in London Bridge, killing eight people, before being shot dead. The Islamic State terror group has claimed responsibility for the attacks and warned of more attacks.

Political parties had called a halt to campaigning both times but Prime Minister May had said that terrorism must not be allowed to derail the democratic process.

May had decided to overturn the UK's Fixed Term Parliament Act, which would have seen an election being held after a fixed five-year term in 2020 and called a snap general election back in April with the aim of winning a strong mandate for Brexit negotiations.

The first results in today's poll are expected to pour in before midnight local time with the final results declared by tomorrow afternoon.

The shape the new government is likely to take is expected to emerge after midnight, with a steady trickle of results until about 2 am when declarations should start to come in from across the UK.

The main wave of results is expected to start at about 3 am with the overall picture likely to be clear by about 5 am on Friday.

The leader of the winning party traditionally waits for the leader of the losing party to concede defeat before claiming victory.

Many of the votes have already been cast through postal voting, which accounted for 16.4 per cent of the total electorate at the 2015 general election.

Overall turnout in 2015 was 66.4 per cent, up from 2010.

Counting will begin immediately after the polls close, with each vote counted and checked by hand.

The weather, which plays a major role in determining the turnout, is forecast for some rain in south-west England, Northern Ireland, Scotland and Wales on Thursday, with southeast England remaining cloudy and dry.

The odds seem to be in favour of May holding on to her job as the British Prime Minister who called for snap polls 52 days ago.

It remains to be seen if the Conservative party leader's decision to call a snap general election follows the forecast patterns of the latest opinion polls and betting odds or the Jeremy Corbyn-led Labour party is able to make a dent into her slim majority in the House of Commons.

Corbyn, 68, has focussed on his party's promise to spend more on health and education.

"Never before has there been a clearer choice between the parties... a choice quite simply between hope and fear," he said.

According to poll forecast, May's ruling Conservatives are believed to have an edge over the Corbyn-led Opposition Labour Party.

May's ruling Conservatives are on 44 per cent, Labour at 34 per cent, the Liberal Democrats at 9 per cent, with farright UKIP at 5 per cent, the Scottish National Party (SNP) at 4 per cent and the Green Party at 2 per cent.

This forecast is echoed in the nearly 100 million pounds expected to be bet on the outcome of the polls.

"Generally, on average, the polls tend to point toward a fairly small Tory majority, whereas the betting is more optimistic of the prime minister landing a majority of around 70 seats," said a betting expert at Ladbrokes, one of the UK’s leading bookmakers.

All the major parties wrapped up their campaigning yesterday with a last-ditch effort to swing undecided voters.

May focussed on her central message of the "strong and stable leadership" that she can provide for Britain's exit negotiations from the European Union (EU).

"Brexit is the basis of everything. We need to secure our economy for the future, we need to ensure we are getting more jobs, better paid jobs, more opportunities for young people in this country. We can do that if we get the Brexit negotiations right," she said in one of her final speeches.

The Liberal Democrats have been focused on their Remainvoting target seats, while the anti-EU UK Independence Party (UKIP) has stuck to its central message of ensuring there is no back-tracking on Brexit.