Boris Johnson has seen his projected Commons majority slashed from 80 to just 12 seats in a week as Jeremy Corbyn’s Labour party eats into the Conservatives’ lead, a poll of polls has revealed.

The survey - based on almost 10,000 voters - shows Jeremy Corbyn closing the gap on the Tories in the same way as Theresa May’s lead collapsed after her manifesto launch and her refusal to appear in TV debates.

Labour is squeezing the Liberal Democrats by gaining Remain voters who see the party as the better prospect to block Mr Johnson’s bid for a rapid Brexit, according to Electoral Calculus which uses socio-economic and past voting data to take account of individual constituencies’ profiles.

Martin Baxter, founder of Electoral Calculus, said the stalling in the Tory vote could explain why Mr Johnson used a speech on Friday to “beat the drum” for working class Brexit votes with pledges on immigration and state aid to protect jobs.

It follows warnings this week by Mr Johnson’s chief of staff Dominic Cummings that a hung Parliament remains “a very real possibility” with Tories and Labour much closer than the polls suggest.

The Electoral Calculus data - which follows all three parties’ manifestos and Mr Corbyn’s “car crash” interview with the BBC’s Andrew Neil - shows the Tories on 41.9 per cent, down from 43 per cent this time last week.

View more!

Labour is up from 29.9 per cent to 32.3 per cent, taking the Conservatives lead below ten per cent for the first time in the election campaign, according to the polls of polls. The Lib Dems have fallen from 15.1 per cent to 13.8 per cent.

Translated into seats, this would give the Conservatives a predicted majority of just 12, with 331 (down 24 seats) against Labour on 235 (up 33 seats), and the Lib Dems on 16, down from 20 last week. The SNP have gained four seats to take 45 constituencies, according to Electoral Calculus.

Mr Baxter said the Conservatives appeared to have stalled after the boost from Brexit Party voters switching to them when Nigel Farage stood candidates down in Tory seats.

This could explain why Mr Johnson used his speech on Friday to pledge his proposal for an Australian-style points system would be in place by January 1 next year and promised a new state aid regime to make it easier for the Government to intervene to protect jobs in trouble, he added.

“He is going out for a working class Brexit demographic with the calculation that there are still some votes in the Brexit party and Leave votes in the Conservative party,” said Mr Baxter.

“Meanwhile, Labour are continuing gradually to squeeze the Lib Dems and the Greens. If they keep going, there is potentially more they can do,” said Mr Baxter.

“The question is whether they have scraped all the Remain voters that they can from the two parties or whether there is more to come.”

View more!

A graph comparing support for Ms May during the 2017 election with Mr Johnson’s shows him below her at the same point in the campaign with the polling suggesting he is on a downward trajectory.

It contrasts sharply with this week’s YouGov constituency by constituency poll, which coincided with Mr Cummings’ warning but which suggested the Conservatives were set to secure a 68-seat majority.

However, Anthony Wells, YouGov director of political research, said the gap was narrowing between Labour and the Tories who “cannot squeeze more than” the three per cent they had out of the Brexit Party. “Labour has more potential votes to squeeze out of the Lib Dems and Greens,” he said.

He said it was significant that the Conservatives were pushing back against the idea that the election “is in the bag.” “They are worried about people thinking it is just about the size of the majority. That might see Remain voters move back to the Lib Dems,” said Mr Wells.

Veteran pollster and psephologist John Curtice said it could “well be the case that the Tories have pretty much hit the high water mark.”

He added: “The Tories may be in a situation where they have to sit and sweat for the next two weeks in the hop that Remain doesn’t get more organised. That’s something over which they have little control and over which they have little influence.”

He said that if there was tactical voting on the scale of 1997, that could take 20 seats off the Conservative total but it would have to be accompanied by a narrowing of the polls.