The Liberal Democrats are on course to be just behind the Tories on 50 MPs, according to the Savanta and Electoral Calculus polling analysis, leaving them in touching distance of becoming the official opposition.

Labour is forecast to have 516 seats and an estimated House of Commons majority of 382 – double that won by Sir Tony Blair in 1997 – as Sir Keir Starmer becomes prime minister.

Meanwhile Reform, despite a surge in the polls, is predicted to get zero seats. For Nigel Farage, the recently returned Reform leader, it would mean an eighth defeat in a row as a parliamentary candidate.

The SNP, according to the poll, is predicted to slump to just eight MPs, down from 48 in 2019, with Labour again the dominant party in Scotland, as it was under Sir Tony.

The polling suggests Tory warnings of a Labour “super-majority” are accurate. It also lays bare the scale of voter disillusionment with the Conservatives, and suggests an uncertain road for the party in the years ahead.

This is the first poll of its kind to forecast Labour to win more than 500 seats. No other poll has predicted that the Tories would win so few seats.

The polling from Savanta for The Telegraph consulted around 18,000 people between June 7 and June 18, capturing views throughout the last fortnight of the election campaign.

The analysis comes from a method called Multilevel Regression and Post-stratification, or MRP, which allows pollsters to take survey results and predict results in individual seats.

In simple terms, it involves talking to many more people than a typical poll – around 10 times more – and drilling down into the demographic details of both respondents and constituencies.

More than 100 seats are predicted to be won by such narrow margins that the pollster believes they remain up for grabs. A small improvement in the Tory vote share could have a marked impact on their seat total.

But the results, published with just a fortnight left before the election, make clear that the Tories are facing a defeat of historic proportions from a frustrated electorate.

In recent weeks, other polling analyses have had the Tories slumping markedly, sometimes to below 100 seats. But none has had them performing quite this badly.

The explanation, according to Savanta, comes in the lead Labour was found to have had over Conservatives, which was 21 percentage points – a little higher than other recent MRP polls.

Savanta’s estimated voting intention has Labour on 44 per cent, the Conservatives on 23 per cent, Reform on 13 per cent, the Lib Dems on 12 per cent, the Greens on four per cent, the SNP on three per cent and Plaid Cymru on one per cent.

The Tories falling so low in nationwide vote share means that not only are they predicted to lose scores of seats to Labour, but also to lose to the Lib Dems in a host of others.

Securing only 53 MPs would comfortably be the Conservatives’ worst result in modern history. It would be less than a third of the 165 they got when New Labour swept to power in 1997.

The modern Conservative Party’s previous lowest number of seats was 131 in 1906. The worst result of the Conservatives’ predecessors, the Tories, came in 1754, when 106 were won.

It would also amount to a remarkable slump from 2019 when the Tories secured 365 MPs under Boris Johnson. It would mean the party keeping just 15 per cent of its 2019 seats.

Mr Sunak is predicted to lose his Richmond seat to Labour, although this race is among those Savanta says are still in the balance given the close margins.

If that were to happen, it would be a moment of history. No prime minister has ever lost their seat at a general election, according to the Institute for Government.

Arthur Balfour is the only prime minister to have come close. He resigned as prime minister in December 1905 and was officially the opposition leader when he lost his seat in the election at the start of 1906.

The predicted result would also have a major impact on who could follow Mr Sunak as Tory leader, given that many of those tipped to run next month if there is a defeat are predicted to lose their seats.

Penny Mordaunt, the Commons Leader, Grant Shapps, the Defence Secretary, Suella Braverman, the former home secretary, and Robert Jenrick, the former migration minister, all lose their seats on this prediction.

So too do Jeremy Hunt, the Chancellor, and James Cleverly, the Home Secretary, meaning that three of the four great offices of state holders would be swept out. The fourth, Lord Cameron, the Foreign Secretary, is not an MP.

Reform – according to the Savanta analysis – would not win any seats, though given the rapid recent changes in the party’s profile, an extra element of doubt could apply to it.

Mr Farage only became Reform leader a few days before this polling began, with an uptick in its vote being seen throughout the last fortnight. His impact on the seat of Clacton, where he is standing, is also hard to predict with nationwide polling.

Reform’s polling increase means only recently has Savanta started putting it among the list of political parties offered up front as an option to respondents, rather than only after the select “other”.

Plaid Cymru would be on four seats. The Greens would get zero seats. Seat projections are not made for Northern Ireland, given polling challenges because of party differences there.

Two other MRP polling analyses were published on Wednesday. The Tories were put on 108 MPs by YouGov and 155 by More in Common, underscoring how small changes in vote share could have significant impacts. More in Common had Labour 16 points ahead of the Tories, in contrast to Savanta’s 21.