It is thought at least 30 MPs have submitted their no-confidence letters, but just 27 have publicly declared their letters. Sir Graham Brady, chairman of the 1922 Committee – which oversees any potential leadership contest – needs to receive 54 letters to meet the 15 percent threshold needed to trigger a vote on whether Mr Johnson should continue in office.
Veteran Tory-watchers claim that the total number of letters can be predicted by doubling the letters declared.
Some Tory rebels believe they are close to succeeding but even if a no-confidence vote does take place there is no guarantee that Mr Johnson will lose.
Mr Johnson requires a majority – just 180 MPs – to support him to keep his position.
As a result, some are keen to postpone any vote of no confidence until late June after two by-elections have taken place and the pressure on Mr Johnson could be higher.
A recent survey of activists conducted by Conservative Home shows that Mr Johnson is the least popular Cabinet minister with an approval rating of -15.
Former Tory leader William Hague forecasts a vote of no confidence over Mr Johnson’s premiership could take place as soon as next week.
Mr Hague told TimesRadio on Tuesday, May 31: “Boris Johnson is in real trouble here and when an MP as reputable, as experienced and respected as Bob Neil, who we were just listening to gives that opinion that he’s just been given that very serious trouble for the Prime Minister.
“I think the Sue Gray report has been one of those sort of slow fuse explosions in politics, it’s still going along.
“A lot of people misread it really the events of last week as meaning the trouble is over, Boris is free and that’s actually not the mood in the Conservative Party that is very, very troubled about the contents of that report.
“So I think that Conservative Party will need to resolve this one way or another, obviously because to be an effective party, they either need to rally behind the Prime Minister they have got or they need to decide to force him out.
“I think they are moving towards either next week or around the end of June, they are moving towards having a ballot that looks like that.”
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