British MPs vote in favour of holding general elections on December 12

British Prime Minister Boris Johnson's December 12 election plan has cleared the House of Commons after MPs backed the date in a vote by a 438 to 20 margin.

It will mark the first December-poll since 1923 once the House of Lords passes the legislation and it becomes law by the end of the week. Once that happens, there will be a five-week campaign up to the polling day.

The development marks a win for British Prime Minister Boris Johnson's bid for a pre-Christmas poll to try and win a public mandate in favour of his Brexit plan.

The UK prime minister can only hold an early election with the support of MPs, who have previously blocked it three times. Efforts by Opposition MPs to lower the voting age to 16 and also allow EU nationals to take part had earlier failed as the changes were not selected for debate by the Deputy Speaker.

But with MPs overall backing a December poll, a pre-Christmas election was certain. One proposed change to the early election motion that was considered was a call by the Labour party, backed by the other Opposition parties, to hold the poll three days earlier, on December 9.

This, they argued, would ensure that university students are more likely to be able to take part in the polling because it would still be in term time.

The prospect of an election became more and more likely after the European Union (EU) had agreed on a three-month extension to the October 31 Brexit deadline. This meant Johnson's "do or die" pledge to leave the economic bloc by Halloween was effectively dead and he was determined to push through an early poll to try and change his current minority figures in Parliament.

Johnson said the public must be "given a choice" over the future of Brexit and the country.

The Labour Party had so far refused to back an early poll until the threat of a no-deal crash out by end of October had been taken off the table, a condition which was met with the new Brexit deadline now being January 31, 2020.

Labour leader Jeremy Corbyn said his party would "now launch the most ambitious and radical campaign for real change that our country has ever seen".