Conservatives could lose more than a dozen seats in their southern and eastern heartlands, shock poll reveals

The Conservatives could lose more than a dozen seats in their southern and eastern heartlands, a shock poll revealed last night.

Support for the Tories in these so-called 'blue wall' constituencies has plunged by eight points since the 2019 landslide, a YouGov survey found.

It suggests that if a general election were held now, the party would lose 12 seats they have always held, with nine going to Labour and the other three to the Liberal Democrats.

Those that would fall include Wycombe, whose MP is prominent Brexiteer Steve Baker, and Chingford and Woodford Green, held by former party leader Sir Iain Duncan Smith.

Support for the Tories in these so-called 'blue wall' constituencies has plunged by eight points since the 2019 landslide, a YouGov survey found (pictured: Iain Duncan Smith, whose seat could be under threat)

A further five constituencies would be on a knife-edge including Esher and Walton, represented by Foreign Secretary Dominic Raab

A further five constituencies would be on a knife-edge including Esher and Walton, represented by Foreign Secretary Dominic Raab.

It comes after the Lib Dems' surprise by-election victory last month in Chesham and Amersham, where traditionally Tory voters were put off by Government policies such as a drive to build more new homes and the HS2 rail link. 

However, Boris Johnson's party remains popular in Labour's former strongholds in the North, having taken Hartlepool in a by-election in May.

Experts believe Brexit has caused a realignment across England with working-class Leave voters switching to the Tories. 

Meanwhile wealthier residents of southern towns and cities are shifting to Remain-backing Labour, Lib Dems or Greens.

YouGov's Patrick English said: 'The results highlight just how difficult a job Boris Johnson has in balancing his new voter coalition. 

'The exact sorts of policies and priorities on issues such as Brexit and investment which are winning him support in the North and Midlands are quite clearly costing him and his party in the South and East.'

But the survey for The Times found that across the UK the Tories still have a five-point lead over Labour – 39 to 34.