Everything you need to know about when a general election is likely to take place

UK election date: which party wants what, and why does it matter?

A December general election now looks all but certain, after Jeremy Corbyn said Labour would be prepared to support Boris Johnson’s latest effort to trigger an early poll.

What is the government proposing?

The prime minister wants an election on Thursday 12 December, with a possible compromise date of 11 December. He originally proposed 12 December, which would have allowed a few more days for MPs to debate his withdrawal agreement bill, and tabled a motion under the Fixed-term Parliaments Act.

That plan failed to win the backing of the required two-thirds of MPs in the House of Commons on Monday night, with Labour abstaining, but Johnson immediately announced he would table a one-line bill, again calling for a 12 December election.

This would require a simple majority to pass, and echoes a plan put forward by the Liberal Democrats and the Scottish National party at the weekend, though they preferred a 9 December date.

What will Labour do?

Corbyn’s party has agonised about whether to support a pre-Christmas poll. The Labour leader has been keen to hit the campaign trail, but some members of the shadow cabinet were very reluctant.

Some had hoped a second referendum could have been secured first, while others would have liked to see Johnson’s Brexit deal debated and agreed, to allow Labour to focus on domestic policies during a campaign.

But Corbyn eventually prevailed and Labour will now back a December election.

Play Video 'I can't wait to get out there': Corbyn confirms Labour backing election – video

Why the row about the date?

Students may have broken up for Christmas by 12 December and it could be harder to get this cohort to vote if they are travelling between two locations. Corbyn brought this point up with Johnson at the dispatch box on Monday night and was heckled by Conservative MPs.

Daylight hours are reduced and in Scotland it is dark at 4pm, or earlier on some of the islands. Some MPs say they are reluctant to go out campaigning in the cold and dark.

Why didn’t Johnson try to get his Brexit bill passed?

The Conservatives say they do not want MPs to try to amend it and risk the bill being stuck in endless parliamentary gridlock.

Some of Johnson’s advisers, particularly those who are veterans of the Vote Leave campaign, have been pressing for an early poll, hoping they can capitalise on the prime minister’s success in securing a deal with the EU and Labour’s discomfort about its Brexit stance.

Why do some parties prefer a 9 December poll?

The Lib Dems and the SNP proposed an election on Monday 9 December to ensure the government had no time to bring its Brexit deal back. They have also warned about the risk of students being disenfranchised.

The Lib Dem MP Chuka Umunna said the party was not prepared to accept the 12 December proposal. “If you have the 12th, it presents an opportunity for the government to get their withdrawal agreement bill through,” he said.

“The reason the 9th is preferable is because it would stop them from bringing forward their withdrawal bill and completing its passage through the Commons.”

Why does the government object to 9 December?

The leader of the Commons, Jacob Rees-Mogg, said the date was not realistic as 25 working days were needed between the dissolution of parliament and polling day. Parliament would have to be dissolved on Friday, while also securing royal assent for the election bill, and passing a Northern Irish budget bill, which could be very difficult.

Which date will win out? Will there be a compromise?

The SNP and the Lib Dems were warmer on 10 or 11 December than 12 December. Labour has suggested it is likely to back efforts to amend the date, but the party is unlikely to withdraw support from the government’s election bill as a result.