The survey of 14,000 people carried out after the local and regional elections across the UK, found the party would take its number of MPs from 46 to 58 – leaving just a single Scottish MP who is not from the SNP.
The SNP secured 48 seats in 2019, but Neale Hanvey and Kenny MacAskill quit the party to represent Alba.
The poll also predicts that Scottish Secretary Alister Jack would lose his Dumfries and Galloway seat to the SNP.
The results showed the Tories would secure a 122-seat landslide majority, up from 81 today, over Labour and win 23 more “red wall” seats in the Midlands and the North of England.
The poll put the Tories on 43%, more than doubling their lead over Labour from 5% before the elections to 13%. The Conservatives would increase their seats by 21 to 386, making gains in Teesside, Sunderland, West Yorkshire and South Yorkshire. Labour fell back 31 seats to 172 seats, with senior politicians including Yvette Cooper, Ed Miliband and Jon Cruddas losing their seats. Pollster Find Out Now and election experts Electoral Calculus ran the poll on voting intention for Westminster for The Telegraph in the wake of the May 6 elections.
A forecast based on those results left the Conservatives with a reduced 36-seat majority. However, in the days since the elections the Tories’ position strengthened significantly.
The experts found that – compared with the 2019 General Election result – Tories would increase their seats by 21 to 386, while Labour would fall back 31 seats to 172.
Chris Holbrook, chief executive of Find Out Now, said Labour was now losing support to the Greens.
He said: “As the successful vaccine rollout continues to endear the Conservatives to a beleaguered nation, Labour’s rebuild seems to have not progressed past the destructive phase.
“The Greens are benefitting particularly at the moment from Labour’s present weakness.”
Martin Baxter, chief executive of Electoral Calculus, said an “existential question is looming large for Labour as its traditional supporters continue to abandon it”.
“The Conservatives now have a double digit-lead over Labour, and could be on course for a landslide majority. A divided opposition with votes split between Labour, Lib Dems and Greens pretty makes it easy for the Conservatives to win.
“Only in Scotland and Wales, where the Conservatives are not the largest party, does their winning formula break down.”