Rishi Sunak's Conservatives at a July 4 election, forecasting the Labour Party would comfortably win a large majority after 14 years in opposition.
Polling by YouGov showed Keir Starmer's Labour was on track to win 425 parliamentary seats in Britain's 650-strong House of Commons, the most in its history. Savanta predicted 516 seats for Labour and More in Common gave it 406.
YouGov had the Conservatives on 108 and the Liberal Democrats on 67, while Savanta predicted the Conservatives would take 53 parliamentary seats and the Liberal Democrats 50. More in Common forecast 155 and 49 seats respectively.
Chris Hopkins, Political Research Director at Savanta, said its projection put Labour on course «for a historic majority».
The three polls were so-called multilevel regression and post-stratification (MRP) surveys, an approach that uses voters' age, gender, education and other variables to predict results in every British voting district. Pollsters used the method to successfully predict the 2017 British election result.
They are largely in line with previous surveys predicting a Labour victory, but show the scale of the Conservatives' defeat could be even worse than previously thought.
YouGov's forecast of 108 seats for the Conservatives was around 32 lower than its previous poll two weeks earlier.
Both Savanta and YouGov predicted that the party of Winston Churchill and Margaret Thatcher could be left with the lowest number of seats in its near 200-year