Jacques KLOPP, Alice RITCHIE

“It hasn’t been this close in years, so obviously voting is very important,” said Adam Banks, one of millions of voters for whom the uncertainty of Thursday’s British general election weighs heavily.

The 28-year-old cast his ballot before work in a north London school, one of thousands of venues transformed on Thursday into makeshift polling stations.

Pubs, churches, town halls and even a windmill are open until 10pm (2100 GMT), as voters choose their local member of the House of Commons in 650 different constituencies.

The party with the most seats will form a government, but at the end of an intense campaign, neither Prime Minister David Cameron’s Conservatives nor opposition leader Ed Miliband’s Labour party looked on course for an outright victory. “It’s been quite an exciting one. It’s been a lot different from other elections we had because we don’t know what the result is going to be,” voter Josh Cook said at the north London school. But for some, the lack of a certain outcome is troubling.

“I wouldn’t say it’s exciting - it’s more unnerving,” said Annette, a 59-year-old community worker voting in a south London park building, who declined to give her surname.

She only decided yesterday how to vote, after reading up on all the parties’ manifestos, but is still not clear exactly what they are all promising. “In the past there’s been a clear demarcation, where with each party you knew exactly where you stood. Whereas now, it’s a shade of grey rather than red, or blue or green,” she said.

‘I’ve done my duty’

If there is no clear winner, the Conservatives and Labour are likely to engage in protracted negotiations with smaller parties to try to form a government. “I slightly dread the next few weeks of cattle dealing before we end up with whatever coalition manages to do the backroom deals,” said James Donald, a communications manager voting in Dorset in the southwest of England.

All the parties have put down their red lines, but he predicted these would become “a little smudged”. Donald did not think his vote will count for much, but said: “I will vote - but more so I can feel I have done my duty and am part of the process.”

The last election saw one of the lowest turnouts in decades, at 65 percent, and many people share Donald’s views, particularly in seats where one party has a large majority.

The confusing election: Vote leaves options open

With all the main opinion polls predicting no party winning a majority in Britain’s general election on Thursday, the stage is set for complex negotiations that could result in four core scenarios.

Informal talks are expected to start as early as Friday once results are in, even as the key political leaders take part in commemorations for the 70th anniversary of the end of World War II.

The first newly-elected parliamentarians could begin making their way to London from Monday, the same day that the Labour Party is expected to hold its first parliamentary party meeting.

Beyond that little is certain except that MPs formally meet on May 18 and Queen Elizabeth II is due to deliver her traditional speech - usually written by the winning side - in parliament on May 27.

At the end of May or in the first week of June, parliament votes on the Queen’s Speech - usually a vote of confidence in the new government. If MPs vote against the policy speech, then the opposition would have two weeks for another vote. And if that vote too falls through, another election would become inevitable - an unprecedented outcome.

Barring this highly improbable worst-case scenario, the four results of the election that are seen as the most likely by pollsters are the following:

1. Conservative-Liberal Democrat coalition: A late boost for the Conservatives and a better-than-expected result for the under-pressure Liberal Democrats could bring the current government line-up back under Prime Minister David Cameron.

If the numbers do not add up to the required 326-seat majority, the Conservatives could also reach out to the Democratic Unionist Party from Northern Ireland.

2. Conservative minority: A more flexible option for Cameron could see the Conservatives going it alone if they end up winning the most seats but then cannot easily put together a multi-party coalition.

Like the Labour version of this scenario, a minority government could spell instability even if it is backed up by a formal agreement as it would leave the Conservatives prey to shifting political sands.

3. Labour-Liberal Democrat coalition: Not a front-runner but things could change quickly in the night between Thursday and Friday, particularly if Liberal Democrat leader Nick Clegg loses his seat.

While Clegg is seen as pro-Conservative, several senior members of the party and many of the rank and file are closer to the centre-left of Labour leader Ed Miliband who would then be the new prime minister.

Smaller left-wing parties like the Social Democratic and Labour Party in Northern Ireland and the Green Party could be brought into this arrangement.

4. Labour minority: Miliband has ruled out any post-election “deal” with the Scottish National Party even though they would be a natural centre-left ally, citing his opposition to their claim for independence. Miliband has left open the option of the SNP voting to support a Labour minority government if they so wish. Conservatives have warned this means that Labour would be “held to ransom” by the SNP.