The Conservatives cancelled the relaunch of their election campaign, as nervousness grew over the party’s evaporating lead in the opinion polls.

Faced with the likelihood of difficult questions about the Tory campaign, David Davis suddenly pulled out of a planned event in central London earlier today.

With Theresa May abroad at the G7 summit in Sicily, it meant the effective relaunch of the Tory campaign, after the three-day pause because of the Manchester bombings, was put on hold.

Ms May would be left with a wafer-thin Commons majority of just two if the swing to Labour in a fresh poll – putting the Tories just 5 points ahead – was replicated in every constituency.

Meanwhile, the Prime Minister’s lead over Jeremy Corbyn in personal approval ratings has shrunk from an astonishing 52 per cent at the start of the election campaign to just 17 per cent.

The Conservatives declined to discuss why Mr Davis had pulled out of the event, a decision taken late last night as news of the YouGov/Times poll dropped.

UK General Election 2017 Show all 47 1 /47 UK General Election 2017 UK General Election 2017 12 June 2017 British Prime Minister Theresa May leaves 10 Downing Street for the 1922 committee on June 12, 2017 in London, England. British Prime Minister Theresa May held her first cabinet meeting with her re-shuffled team today Getty Images UK General Election 2017 12 June 2017 DUP leader Arlene Foster stands alongside deputy leader Nigel Dodds as they hold a press conference at Stormont Castle as the Stormont assembly power sharing negotiations reconvene following the general election on June 12, 2017 in Belfast, Northern Ireland. Discussions between the DUP and the Conservative party are also continuing in the wake of the UK general election as Prime Minister Theresa May looks to form a government with the help of the Democratic Unionist parties ten Westminster seats. 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Perhaps significantly, the Prime Minister would have been in the air, en route from Brussels to the G7 summit, making the Tory strategy more difficult to discuss and decide.

The YouGov/Times poll shows the Conservative lead has shrunk from 24 points to 5 points in a month, the smallest margin since the middle of the EU referendum campaign.

Labour – at 38 per cent – is enjoying its highest level of support since October 2014, under Ed Miliband.

And Ms May’s personal approval ratings have dropped from 10 per cent to just 1 per cent – while Mr Corbyn’s have risen from minus 42 per cent to minus 16 per cent.

If the poll is repeated universally on June 8, Labour would take eight seats from the Conservatives, in places as far spread as Croydon, Plymouth, Derby and North Wales, while the Tories would fail to gain any from Labour.

The poll has also taken the temperature during the peak period for people returning postal ballots. Postal votes made up 21 per cent of ballots cast in 2015.

The survey was carried out after Ms May’s humiliating U-turn over her initial refusal to cap lifetime care costs and the collapse of several of her manifesto proposals.

However, following the Manchester atrocity, attention is now likely to focus on the stance of the party leaders on security issues, police funding and the threat of terrorism.