The Tories have surged so far ahead that they could win 65 seats from Labour in England and Wales, as well as up to 12 seats in Scotland, according to a new series of polls.
Theresa May could also rewrite the electoral record books by winning the most seats in Wales for the first time since the 1850s.
If the polls were repeated on June 8, it would put the Conservatives on course for around 400 seats, with Labour reduced to around 160, reversing the state of the parties after Labour’s modern-day record majority of 179 after the 1997 landslide.
It confirms Labour’s worst fears that Jeremy Corbyn’s disastrous poll ratings, combined with Mrs May’s growing popularity, particularly with working class women, will lead to a doomsday scenario for Labour at the snap election.
It comes as Theresa May urges Labour voters to abandon “tribal politics” and consider “the future” when casting their vote, as she tries to steer the agenda back to Brexit.
On Tuesday Mrs May will visit South Wales, deep in Labour’s heartlands. In an article for the Western Mail today, she tells Welsh voters - who backed Leave in the EU referendum - that she alone can deliver the “strong and stable leadership” needed to “see us through Brexit and beyond”.
An ITV Wales/YouGov poll has put the Tories on 40 per cent in Wales to Labour’s 30 per cent, which would give the Conservatives 21 seats in Wales to Labour’s 15. Labour has won the most seats in Wales at every election since 1922, and the Conservatives have not won overall in the principality since they were fighting the Whigs during the early Victorian era.
While the Conservative hierarchy has warned against complacency and pointed out that polling has proved unreliable in recent elections, results in Wales have followed polls much more closely than in other parts of the country.
The Conservatives are expected to benefit from a collapse in support for Ukip in Wales, down in polling from 13 per cent to 6 per cent since January, with two thirds of Ukip defectors saying they will vote Tory.
The most eye-catching poll of the day, carried out by ICM for The Guardian, suggested the Conservatives now have a lead of 17 per cent in marginal seats where Labour have a majority of 15 per cent or less.
That would mean Labour losing 65 seats to the Tories, a swing of 130 seats between the two parties.
Martin Boon, of ICM, said the figure should be treated with caution because of a small sample size, but added: “It indicates significant losses for the Labour Party, and puts the Conservatives on course for around 400 seats.”
The Guardian/ICM poll gave the Tories a 21 per cent lead overall, with 48 per cent to Labour’s 27 per cent, in keeping with other recent polls. The Liberal Democrats had 10 per cent and Ukip 7 per cent.
In Scotland, the latest polls have put support for the Conservatives as high as 33 per cent, which would be enough for 12 seats north of the border, including 10 won from the SNP.
Mrs May is also expected to warn Welsh voters that a Labour commitment to borrow £500 billion to fund a grand spending spree after Carwyn Jones, the Welsh Labour leader and First Minister of Wales, justified it by saying “there’s never been a better time to borrow. It’s cheap”.