Constituency polling in London’s Remain-backing commuter belt has revealed signs of a “seismic” swing away from Boris Johnson’s Conservatives which could see arch-Brexiteers like John Redwood unseated in the 12 December general election, Liberal Democrats have claimed.

A Survation poll commissioned by the party in Sir John’s Wokingham constituency, obtained by The Independent, found the Tory vote plummeting 15 points since the 2017 general election to 42 per cent, with Lib Dems just four points behind on 38 per cent – up 22 points.

With Labour down 13 points to 12 per cent in the poll, Jo Swinson’s party said the Berkshire seat was now “a two-horse race” with Lib Dems closing in on Redwood.

A party source said the pattern was being repeated in many areas of the leafy commuter belt around the capital, suggesting “massive” swings among traditional Tory voters against the “Trumpian right-wing politics” ushered in by Mr Johnson.

Survation polling in South Cambridgeshire – held by Tories for almost 30 years until Heidi Allen’s defection in February – showed Lib Dems picking up 21 points to leapfrog the two larger parties on 40 per cent, with Tories down 16 points to 36 per cent and Labour down 15 to 12 per cent.

While a majority of Conservative seats across the country backed Brexit in 2016, a swathe of true-blue Tory constituencies, like St Albans, Guildford, Esher & Walton – held by foreign secretary Dominic Raab - HItchin & Harpenden and Chipping Barnet voted strongly to Remain.

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Some 57 per cent of voters in Wokingham voted Remain in 2016, and the Brexit-opposing Lib Dems came top in the area in this year’s European elections.

Former Tory MP Phillip Lee, who dramatically defected to the Lib Dems by crossing the floor of the Commons as Mr Johnson spoke, is challenging former cabinet minister Sir John.

Dr Lee said: “Across the constituency, life-long Conservatives have been telling us they feel deserted by the party under Boris Johnson. The message is clear; they will not support a party and a MP that no longer reflects their own values.

“On the other side of the coin, Labour supporters have recognised that there is now a real chance of removing an MP who has failed to represent their views for last 32 years.

“Every vote for the Liberal Democrats at this election is a vote to stop Brexit so we can build a brighter future with our ambitious plans for schools, public services and tackling the climate emergency.”

Sir John Redwood, who has represented Wokingham since 1987 declined to comment on the poll when contacted by The Independent.

Phillip Lee with Lib Dem leader Jo Swinson (EPA)

A Liberal Democrat source said: “Right across many London commuter belt seats we are seeing massive swings away from the Conservatives towards the Liberal Democrats.

“It is clear the lurch towards Trumpian right-wing politics under Boris Johnson has created a seismic shift. Our unequivocal commitment to stop Brexit is seeing more and more people lend us their vote.”