Both Labour and the Conservatives have lost ground in all regions of Britain since the 2017 vote, as Liberal Democrat and Brexit Party support surges in an election dominated by relations with the EU.
But the YouGov findings make the grimmest reading for Mr Corbyn, who sees Boris Johnson’s Conservatives establish a lead in the northwest and Yorkshire and Humber regions and challenge Labour for supremacy in the northeast.
Meanwhile, Jo Swinson’s Liberal Democrats have pulled ahead of Labour in large swathes of the south, emerging into second place behind the Tories in the southeast, southwest and east of England regions.
And Labour fell behind the Lib Dems into fourth place in Scotland, where the party ruled the roost as recently as 2010.
In Wales, Labour clung on by its fingertips to a one-point lead over the Tories – down from a 15-point margin in 2017.
The poll of 11,590 voters, carried out between 17 and 28 October, gave the Tories a comfortable overall lead on 36 per cent to Labour’s 22 per cent and the Lib Dems’ 19 per cent.
But it bolstered theories that both of the two major parties are losing votes in either direction to smaller rivals standing on clear pro- and anti-Brexit tickets.
Mr Johnson’s figures were down in every part of the country on those achieved by Theresa May in the 2017 election, when she took 42 per cent to Labour’s 40 per cent and the Lib Dems’ 7 per cent, producing a hung parliament.
Nevertheless, Tory strategists will take heart at the party’s position in the vital northern seats where Mr Johnson is targeting “Workington man” – traditional Labour voters who backed Leave in the 2016 EU referendum.
Labour’s share of the vote in the northwest region – including Workington as well as the party’s fortresses in Lancashire, Merseyside and Greater Manchester – has collapsed from 55 per cent to just 30 since the 2017 election, leaving Mr Corbyn’s party three points behind the Tories on 33 per cent.
In the Yorkshire and Humber region, Labour’s decline was almost as precipitous – down 20 points since 2017 from 49 to 29 per cent, five points behind the Tories on 34.
In the northeast, Labour’s vote was down 23 points since the last election from 55 to 32 per cent. But Mr Corbyn’s party held onto its lead in the region as the Tory share of the vote fell from 34 to 26 per cent over the same period.
The PM visited George Spencer Academy in Nottinghamshire on Friday (AFP/Getty)
The northeast recorded the strongest support for Nigel Farage’s Brexit Party at 19 per cent – up 15 points from Ukip’s 4 per cent in 2017.
In the West Midlands, the Tories extended their six-point lead over Labour in 2017 to 20 points on 43 per cent (down six) to Labour’s 23 (down 20). The Lib Dems were up 10 points to 14 per cent and the Brexit Party were on 12.
A similar pattern was recorded in the East Midlands, where Labour shed 19 points to hit 22 per cent, 23 points behind the Tories on 45 per cent (down six). The Lib Dems were on 15 per cent and the Brexit Party 12.
In the south, the Liberal Democrats appeared to establish themselves as the main challengers to the Tories outside London.
In the southeast – where Ms Swinson’s party is targeting a number of Remain-voting Tory commuter belt seats – the Lib Dems were up 12 points since the last election to 23 per cent, ahead of Labour on 16 (down 13) and the Brexit Party on 12, but still a long way behind the Tories on 41 (down 13).
The Lib Dems were on 21 per cent in the southwest (up six), pulling ahead of Labour on 17 (down 12) and the Brexit Party on 13, with the Tories maintaining a comfortable lead on 41 per cent (down 10).
And in the east of England, the Lib Dems were up 10 points since 2017 to 18 per cent, one point ahead of Labour on 17 (down 16) and four ahead of the Brexit Party on 14, but still well behind the Conservatives on 45 (down 10).
Only in London did Labour record a comfortable lead of 10 points over the Tories, but even in the capital, its rating was 16 points down from the 55 per cent recorded in 2017, on 39 per cent. The Conservatives were down four on 29 per cent and the Lib Dems up 10 on 19 per cent.
In Wales, Labour had lost 20 points since 2017 but maintained a bare one-point lead on 29 per cent to the Tories’ 28, with the Brexit Party in third place on 15, with Plaid Cymru and the Lib Dems both on 12.
Nicola Sturgeon’s Scottish National Party consolidated its dominance north of the border, increasing its share of the vote from 37 per cent in 2017 to 42 per cent now. Tory support fell seven points to 22 per cent and Labour slumped 15 points to 12 per cent, while the Lib Dems put on six points to 13 per cent. If replicated on polling day, Labour’s 12 per cent tally would be the party’s worst performance in Scotland for 100 years.
The Greens improved on their 2017 performance in every part of the country, scoring 7 per cent in the northeast, Yorkshire and Humber, the West Midlands and the southwest.