Britain's Prime Minister Boris Johnson tries some cider as he visits Healey's Cornish Cyder Farm during the General Election campaign in Callestick, England. Picture: Dan Kitwood/Pool Photo via AP

London - The Conservatives of British Prime Minister Boris Johnson are set to win a comfortable majority in the upcoming general election, according to a new poll.

Brits will go to the polls for a snap general election on December 12 after parliament refused to rush through the Brexit divorce deal Johnson negotiated with the European Union.

A model by pollster YouGov released on Wednesday projects that the Conservatives will win 359 of the 650 seats in the Commons, 41 seats more than the party won in the 2017 general election and 61 more than it currently has following a number of defections over Johnson's Brexit course.

The opposition Labour party, which lost 19 lawmakers protesting at the way party leader Jeremy Corbyn is dealing with anti-Semitism and handling Brexit, is projected to win 211 seats, a 51-seat drop compared to 2017.

A screengrab from the website

Meanwhile the Scottish National Party (SNP) would gain a further eight seats to 43, while the Liberal Democrats, who won 12 seats but received some of the defectors for a total of 20 seats in the Commons, are projected to win 13 seats.

YouGov's seat-by-seat analysis, commissioned by the Times newspaper, is considered authoritative as it correctly predicted a hung parliament in 2017.

Most political analysts believe the most likely outcome of the election is a comfortable parliamentary majority for Johnson's Conservatives, from a vote share of about 44 per cent under Britain's constituency-based, first-past-the-post system.