Jeremy Corbyn is within touching distance of pulling off a shock win in Islington North, according to a new poll.
The MRP survey by YouGov has Labour beating its former leader, who is standing as an independent.
But the race in this north London constituency is so tight that YouGov describes it as a “toss up”.
The pollster classified this seat as such as this contest could be settled by fewer than five points.
It put Labour on 41 per cent, with Mr Corbyn on 36 per cent.
As the general election hots up, The Evening Standard has drawn up an interactive map of all the key battlegrounds in London on July 4.
The YouGov poll also showed the political establishment facing a second potential blow, with Reform UK leader Nigel Farage set to win in Clacton, which would make him an MP at the eighth time of trying.
Reform UK is also in line for second place finishes in eight London seats, taking around 27 per cent of the vote in Dagenham and Rainham, according to the survey.
Mr Farage’s party is set to win around a fifth of the vote in five seats (including two that are tight Labour/Tory races) which are Bexleyheath and Crayford, Hornchurch and Upminster, Romford and Old Bexley and Sidcup, as well as Dagenham and Rainham.
Ahead of the election, Labour chiefs refused to allow Mr Corbyn to stand as their candidate in the seat he has represented since 1983, after the anti-semitism storm during his leadership.
Local Labour councillor Praful Nargund is instead the party’s candidate.
But Leftwinger Mr Corbyn has a strong local following and this race appears to still be open as to who will win.
If the former leader did pull off a surprise win it would be a blow to Sir Keir Starmer.
Some Labour party members in Islington North have accused the leadership of acting undemocratically in blocking them from selected Mr Corbyn as their candidate, a claim rejected by Sir Keir.
The Tories are set to lose a string of seats across London on July 4, according to the poll.
They would be left with just six constituencies: Bromley and Biggin Hill, Finchley and Golders Green, Hornchurch and Upminster, Orpington, Romford, and Ruislip, Northwood and Pinner.
The Conservatives would be wiped out in Inner London, losing Cities of London and Westminster, Chelsea and Fulham, and the new constituency of Kensington and Bayswater.
The Liberal Democrats would also gain three seats from the Tories; Wimbledon, Sutton and Cheam, as well as Carshalton and Wallington.
The Conservatives are on course to finish second in 32 constituencies in London, though three of them are “toss ups” – Croydon South, Harrow East, and Old Bexley and Sidcup, where Labour is narrowly ahead in all three.
YouGov said its latest study projects Labour is on course to achieve a 200-seat majority nationwide.
Labour is predicted to secure 425 seats, the Tories 108, the Liberal Democrats 67, SNP 20, Reform UK five, Plaid Cymru four and the Green Party two.
YouGov used a technique known as MRP (multi-level regression and post-stratification) to model the outcome of the election in every constituency across Britain.
It said the estimated seat projections were based on modelled responses from 36,161 adults in England and Wales, and 3,818 in Scotland.