Boris Johnson is on course for a resounding victory in Britain’s general election, with a Conservative majority of 86 seats, according to an exit poll released after polls closed.

The poll, which has been broadly accurate in five out of the last six British elections, put the Conservatives on 368 seats, with Labour recording its worst result in modern history with 191 seats.

The Scottish National Party (SNP) are predicted to win 55 seats, capturing all but four of Scotland’s constituencies, with the Liberal Democrats winning 13 seats, just one more than in 2017.

If the exit poll is accurate, Mr Johnson will command the biggest Conservative majority since Margaret Thatcher’s third election in 1987. He will be able to pass his withdrawal agreement through Parliament without difficulty and take Britain out of the European Union on January 31st.

Mr Johnson will introduce his legislative programme in a Queen’s Speech next Thursday and will bring the withdrawal bill back to Parliament before Christmas.

Thank you to everyone across our great country who voted, who volunteered, who stood as candidates. We live in the greatest democracy in the world. pic.twitter.com/1MuEMXqWHq — Boris Johnson (@BorisJohnson) December 12, 2019

The result would be catastrophic for Labour, which had risen in the polls in the final weeks of the campaign and is likely to prove fatal for Jeremy Corbyn’s leadership.

“If it is anywhere near this, it will be extremely disappointing,” Labour’s shadow chancellor John McDonnell told the BBC.

The SNP’s success in Scotland will encourage the party in its demand for a second referendum on independence. And the Liberal Democrats’ poor result will raise questions about Jo Swinson’s leadership.

It was Britain’s first December general election but there were queues outside polling stations in parts of London, Manchester and Cambridge as voters defied the cold, wind and rain that affected much of the country.

The Conservatives enjoyed a comfortable opinion poll lead over Labour throughout the campaign, although the polls began to narrow in recent days.

People queue to vote in the general election in London. Photograph: Hannah McKay/Reuters

The five-week campaign was dominated by Brexit, the National Health Service (NHS) and the character and leadership qualities of Boris Johnson and Jeremy Corbyn. The Conservatives sought to maintain the focus on Brexit, characterising the election as an opportunity to break the gridlock at Westminster by taking Britain out of the EU within weeks.

Labour tried to shift voters’ attention away from Brexit to the impact of almost a decade on Conservative government on public services. The party faced questions about its handling of allegations of antisemitism and scepticism about its spending plans, which included a promise to introduce free, high-speed broadband to every home and business in the country.

A man was arrested after a suspicious device was found in a polling station in North Lanarkshire hours before voting was due to begin. Police carried out a controlled explosion on what they described as a “non-viable” device and the polling station was moved to a different venue.