EXCLUSIVE: Boris Johnson warned June 24th will be his 'Black Friday' in moves to topple him

Senior Tories say backbench shop steward Sir Graham Brady may wait until the day after key by-elections in Devon and Wakefield before counting letters of no confidence in the PM

Boris Johnson has been warned to pencil in June 24th as his Black Friday when moves to topple him could begin.

Senior Tories say backbench shop steward Sir Graham Brady may wait until the day after key by-elections in Devon and Wakefield before counting letters of no confidence in the PM.

The chair of the 1922 Committee needs 54 to trigger a vote of all Tory MPs. The PM will be a goner if fewer than 180 of his MPs support him.

Sir Graham never reveals how many letters he has until the target figure is reached. Theresa May was surprised to find it was double the estimate when she was challenged in 2018.

So far 48 MPs have said they have lost faith in the PM over partygate, and 28 have admitted publicly to writing letters.

One top Tory said: “Graham wasn’t going to do anything to spoil the Queen’s Jubilee celebrations.

“But he may feel he does not want to influence the by-elections either. He can do that by simply not opening the letters he has received.”

And Sir Graham said: “I shall retain my discretion. Looking at them is not a regular pastime of mine.”

Last week former Cabinet minister Andrea Leadsom criticised the PM but stopped short of saying whether she had submitted a letter.

One former Cabinet minister said: “She was a leadership challenger herself so she has a hard core of supporters.

“If she does send a letter in then there will be at least another five MPs who will do the same.”

The Tories now expect to lose Wakefield to Labour but they are most worried about the Lib Dems overturning their 24,239 majority in Tiverton and Honiton vacated by tractor porn MP Neil Parish.

Mr Johnson has been frantically phoning around waiverers promising them ministerial jobs in a July reshuffle.

But one MP said: “He promised me a job in 2019 when I campaigned for him. I didn’t get one.”