Boris Johnson is on course to win the General Election with a comfortable 68-seat majority by triumphing in Labour heartlands, according to a projection poll which accurately forecast the hung parliament in 2017.

The constituency-by-constituency estimate by YouGov, published in The Times, indicates that if the election was held on Thursday, the Conservative Party would win 359 seats, 42 more than they took in 2017.

It would also take 43% of the vote, and in number of seats this would be its best performance since 1987.

Labour, meanwhile, is set to lose 51 seats, falling from 262 seats in 2017 to 211 now, and taking 32% of the vote, a nine percentage point decrease.

This would be the party’s worst performance in seats won since 1983, YouGov said, adding that the opposition is on course to not take any new seats.

Of the 76 Labour-held seats where it leads the Tories by fewer than 8,000 votes, Jeremy Corbyn’s party is currently behind in 43 of them, according to the analysis which has been released just over two weeks before polling day.

YouGov used the same method in the 2017 general election, when it accurately predicted the results in 93% of constituencies and pointed towards a hung Parliament.

Chris Curtis, political research manager at YouGov, said the current analysis shows the Tories have a “comfortable majority”, with seats coming their way at the expense of Labour in the North and Midlands.

“As expected, the key thing deciding the extent to which each of these seats is moving against Labour are how that seat voted in the European Union referendum.

“In the seats that voted most strongly to Leave in 2016 (60% or more in favour of departing the EU), the swing to the Conservatives is over 6%.

“This is allowing the Tories to overturn quite substantial majorities in places like West Bromwich East, the seat held until recently by Tom Watson, and Don Valley, the seat currently held by Caroline Flint.

“The only silver lining for Labour is that there are still 30 seats where it is currently 5% or less behind the Tories.

“If it can manage to squeeze the gap over the coming fortnight, it may be able to paste over the cracks in their so-called Red Wall. But with just two weeks to go, time is running out for Labour.”

Shadow Health Secretary Jonathan Ashworth said if the poll is correct it will be a “thumping great victory” for Prime Minister Boris Johnson.

He told ITV’s Peston that people are going to have to start thinking about whether they really want Mr Johnson for the next five years running the NHS which he said has waiting lists of 4.5 million, adding: “How much worse are those waiting lists going to get if Boris Johnson has got a victory of that size?”

Baroness Warsi, former Conservative Chair, told the programme it is good news and bad news for the Tories, explaining: “Good news because I think secretly we’ll be quite confident that this is exactly where we needed to be at this stage, and so far the election campaign has gone to plan.”

But she said it is bad news as there will now be a concern that people who would have voted Tory may now feel they do not need to bother.

Meanwhile, the Liberal Democrats are currently on course to see their number of MPs increase by just one from 12 to 13, picking up four new seats while losing out in three they currently hold.

The SNP is on course to secure a further eight seats, although crucially for the Tories’ chance of securing a majority, only two come from Mr Johnson’s party (Stirling, and East Renfrewshire).

By contrast, Labour is set to lose five seats to the SNP, with the Lib Dems losing one in Scotland, the figures show.

The Greens will still have one seat, while Plaid Cymru will still have four, according to the data.

YouGov’s model draws on data collected from about 100,000 panellists questioned on their voting intention over the course of the last seven days, and uses a recently-developed technique called multilevel regression and post-stratification (MRP).

A separate poll, by The Daily Telegraph and Savanta ComRes, has the Conservatives on 41%, down one point from the weekend, while Labour rises two points to 34% at the expense of the Liberal Democrats, who drop two points to 13%.

The pollster said that according to voting analysis website Electoral Calculus, if the parties were to achieve these vote shares at a general election it would result in the Tories having a narrow majority of 10.

The projections came as Mr Johnson’s top aide Dominic Cummings warned the election race was “much tighter” than the opinion polls suggested.

He said Leave supporters risked handing victory to Labour if they voted for Nigel Farage’s Brexit Party in key marginals the Tories need to take if they are to gain an overall majority.

The YouGov model seems to suggest the Brexit Party is hurting the Conservatives more than Labour in some neck-and-neck marginals where Nigel Farage’s party is running.