MAPPED: The six knife-edge seats where Reform could pip Labour to the post and tilt the balance of power

Under the polling, the new Reform UK seats are almost exclusively constituencies which are estimated to have voted Leave in the 2016 EU referendum.

Of these gains, here's a look at some of the most marginally-held.

Poole

The Dorset seat was one of the closest fought battlegrounds at the last election.

It took three recounts to confirm the end of Tory MP Sir Robert Syms' 27 years as an MP, with Neil Duncan-Jordan becoming the first Labour MP to hold the seat with a majority of just 18 votes.

Under the new YouGov Polling, Reform takes 31 per cent, with the Conservatives on 22 per cent and Labour on 20 per cent.

North West Cambridgeshire

Another Labour newcomer who overturned a Tory veteran is Sam Carling who beat Shailesh Vara, who had represented North West Cambridgeshire for almost two decades, winning by just 39 votes.

Carling made parliamentary history becoming the first person born in the 21st Century to be voted into the Commons and is the current youngest MP.

However, his time may be short lived as Reform are tipped to win the seat on 32 per cent, with the Conservatives on 25 per cent and Labour on 23 per cent.

Peterborough

In adjacent Peterborough, Labour candidate Andrew Pakes beat the incumbent MP Paul Bristow by 118 votes.

Bristow, who had held the seat since 2019, has now gone on to be the one bright spot in the dire local elections for the Conservatives, becoming the Tory Mayor of Cambridgeshire and Peterborough.

However, the Tories and Labour could be swept aside with Reform UK on 28 per cent with both Labour and the Conservatives behind on 23 per cent.

Forest of Dean

In one of many devastating blows for frontline Conservative politicians in 2024, then-Transport Secretary Mark Harper was unseated his Forest of Dean seat by Labour's Matt Bishop by 278 votes.

Harper, who had held the seat since 2005, was unseated by Bishop, a former police officer turned politician.

Reform UK are projected to take the seat on 32 per cent, with the Conservatives behind on 22 per cent and Labour on 20 per cent.

Derbyshire Dales

In one of the more peculiar tales of last year's General Election, former vocalist for cult funk-metal band The Beyond, John Whitby, unseated incumbent Conservative Sarah Dines in the Derbyshire Dales seat.

Whitby won the seat with a majority of 350 votes after standing down as Mayor of Derby.

However, if the YouGov polling is accurate, Nigel Farage's party would clinch the seat from Whitby on 29 per cent, followed by the Conservatives on 24 per cent and Labour trailing behind on 22 per cent.

Sittingbourne and Sheppey

Sittingbourne and Sheppey returned a Labour MP for the first time in 14 years after self-professed "Lego geek" Kevin McKenna beat former international swimmer and Conservative candidate Aisha Cuthbert.

The Kent seat, once held by outspoken Brexiteer Gordon Henderson, was won by Labour with a majority of just 355 votes.

If the YouGov polling proves accurate, Reform would storm in front on 39 per cent, with Labour on 21 per cent.