Could we be back where we started come Friday morning?

Well, there is a possibility we could see another hung parliament. Here's some information about what that could mean.

So, what is a hung parliament?

A hung parliament happens when no overall majority is won by a party in the House of Commons at a general election.

A party needs 326 seats for a nominal majority; there are 650 seats in Parliament in total.

Who is prime minister if a hung parliament happens?

The prime minister who was in power before the election stays in power if there is a hung parliament. So that would mean Boris Johnson would stay Prime Minister until arrangements are sorted and he can recommend a successor to the monarch.

It gives him the chance to create a government by negotiating with another party with form a coalition.

Or the other option is, he resigns should a coalition not be possible with another party.

In this case, the prime minister would then usually recommend that the leader of the largest opposition party attempts to form a government either through a coalition or with a minority.

A minority government can command confidence, but if it failed to pass an important vote, say for instance the Queen's speech, that would demonstrate a loss of confidence.

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Prime Minister Boris Johnson delivers milk to Debbie Monaghan in Guiseley, ahead of Thursday’s General Election (Stefan Rousseau/PA)

How common are hung parliaments?

We’ve experienced two hung parliaments in recent years according to

In 2017 the Conservative Government lost its majority and entered into a supply and confidence agreement with the Democratic Unionist Party.

The 2010 General Election also produced a hung Parliament. The Labour Government remained until a majority government could be formed. A coalition government was formed between the Conservatives and Liberal Democrats.

Before that in 1974 the incumbent Conservative administration lost its majority. Edward Heath remained as Prime Minister for a few days while he tried to form a coalition. But a few days later he had failed to form a coalition and resigned as Prime Minister.

In a second general election that year, Labour was returned with an overall majority of three. By 1977-78 the Labour Government had to draw on the support of the Liberal Party. They formed a Lib-Lab pact which lasted until May 1978.

And in 1923 the Conservative party lost their majority at the general election. It was unable to form a coalition. The party, led by Stanley Baldwin, lost a vote on the King’s speech in January 1924 and the Labour party then took office and governed as a minority administration until October of that year.

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Labour leader Jeremy Corbyn joins a phone banking session with party activists at the Scottish Labour Party headquarters in Glasgow (Jane Barlow/PA)

How likely is it we get a hung parliament this time?

We hate to be the bearer of bad news (yes really we do), but it is a possibility.

Aside from the warnings from Mr Johnson’s Conservatives about the “clear and present” danger of a hung parliament, one of the latest polls has suggested it could be on the cards.

The opinion polls have consistently shown the Conservatives ahead of Labour, but leading Tory figures - including Mr Johnson's chief adviser Dominic Cummings - have warned the race is much tighter.

The Lib Dems have insisted they would not put Mr Corbyn in No 10 while Labour have said that in the event of a hung parliament they would seek to form a minority government rather than enter into any formal pacts or coalitions with other parties.

YouGov’s constituency-by-constituency poll predicts the Conservatives are on course for a 28 seat majority – but the margin of error and unknown impact of tactical voting means a hung parliament is still a possibility.

The pollsters, who have analysed more than 100,000 voter interviews over the past week, predicted the Tories will win 339 seats and Labour 231.

A 28-seat majority would be the best Tory result since Margaret Thatcher’s showing in 1987 – but it is down from the sizeable 68-seat victory that the same YouGov-style poll had been predicting only two weeks ago.

Chris Curtis, YouGov’s political research manager, said: “The margins are extremely tight and small swings in a small number of seats, perhaps from tactical voting and a continuation of Labour’s recent upward trend, means we can’t currently rule out a hung parliament.”

The result will be a worry to Mr Johnson as he prepares for a final blitz across the country as the campaign enters its final full day, with Tory gains off Labour reduced from 44 to 29 since the November 27 findings.

While the polls have improved for Jeremy Corbyn’s Labour Party, the haul of 231 seats would mean a loss of 31 seats compared to 2017’s outcome – its worst result since the 1980s.

The SNP would win 41 seats – up by six – and the Liberal Democrats 15 if the prediction bears out.

Plaid Cymru would hold onto its four constituencies and the Green Party its one, while Nigel Farage’s Brexit Party would finish the election empty handed, polling predicts.

Which seats could change?

According to YouGov, Labour could be set to make two gains, pulling off a Cabinet minister scalp by taking Chipping Barnet, the constituency currently held by Environment Secretary Theresa Villiers.

Foreign Secretary Dominic Raab is in trouble to the Liberal Democrats in Esher and Walton, while former Tory leader Iain Duncan Smith in Chingford and Woodford Green is clinging on by only two points against Labour, the poll result indicates.

Putney could also go red but YouGov continues to predict a tough time for Labour in its heartlands in the North and Midlands.

Veteran MP Dennis Skinner’s Bolsover seat could be taken by the Tories, as could constituencies such as Great Grimsby, a Leave-voting town represented by Labour since the Second World War.

How is this polling calculated?

YouGov uses multilevel regression and post-stratification (MRP) to form its predictions – a model that predicted 93% of constituencies correctly in the snap election two years’ ago.

The polling company first models voting preferences based on age, gender, education and previous votes, along with local political circumstances, before applying MRP, a technique which adds local factors and individual characteristics of each of Great Britain’s 632 constituencies to come up with its final result.