THE osmosis of Conservative rebellion is, it seems, gathering pace. More Tory MPs are spending Westminster’s Whitsun recess searching their souls and finding reasons for staying loyal to Boris Johnson falling away.

As the country enjoys the extended Platinum Jubilee weekend, celebrating the Queen’s historic tenure, the PM has his mind firmly on his own and how to rid himself of the millstone that is Partygate, which he described as a “totally miserable experience”.

Johnson has spent much of the recess on the blower, pleading with colleagues to stay loyal. Operation Save Big Dog is back in full swing.

There are now some 30 Conservative MPs who have called for Johnson to go among 44 who have questioned his leadership. Some 54 signatures are needed to trigger a confidence vote and 180 Tory MPs would need to vote against their leader to oust him.

Most notably, those who have spoken out against Johnson now include Sir Jeremy Wright, the former Attorney General, and ex-Cabinet colleague Andrea Leadsom, who denounced the “unacceptable failings of leadership” in Number 10. They are hardly the usual suspects.

It would only take one serving Cabinet minister to follow suit and resign to send Boris into a new dimension of danger. Where one goes, others could follow.

This week, Lord Hague, the former party leader, argued the PM was now in "real trouble," saying: “The fuse is getting closer to the dynamite here and it’s speeding up. So, that’s just another indication the Conservative Party is moving faster towards a vote of confidence.”

However, some MPs are said to be holding back from submitting letters of no confidence, fearing their names will be leaked and they will face reprisals from the party whips.

One senior Tory suggested he had offered to take letters to the Westminster office of Sir Graham Brady, who chairs the party’s backbench 1922 Committee, on behalf of colleagues concerned about leaks and corridor-snooping snitches.

Intriguingly, some Cabinet ministers are said to want Johnson to “force the issue” by holding a confidence vote ahead of the two by-elections in Wakefield and Tiverton on June 23 for fear that staging one after losing the seats could boost the numbers against him.

Cabinet insiders say Johnson thinks he will win any confidence vote. One told the Times: “He doesn’t care whether he wins by 100 or 10; he will plough on. Colleagues are frothing at the mouth in a way the public is not.”

The PM’s confidence may rest on the fact the Government’s current payroll vote of ministers and private parliamentary secretaries numbers 173, meaning there are 186 Tory MPs on the backbenches. So, getting 180 rebels looks very difficult.

And yet, it’s supposed to be a secret ballot and no one should know how MPs have voted. However, I was once told the whips have nefarious ways of finding out who voted which way. No one ever explained how.

The problem for Johnson is that while the chances are he would win a confidence vote, the numbers could be too close for comfort for loyal colleagues. While under the current rules he would survive another year without challenge, it could prove to be an extended period of backstabbing. The October party conference, always a cauldron of conspiracy, would only exacerbate the divisions.

In an interview with Mumsnet this week, Johnson admitted to having considered resigning but dismissed the idea, insisting he would not “abandon the project” because it would not be "responsible right now given everything that's going on".

Reinforcing the concern within Cabinet, a number of allies have taken to the airwaves to dismiss talk of a confidence vote. One denounced the rebels as “self-indulgent, narcissistic and contemptuous”.

Yesterday, Priti Patel, the Home Secretary, urged those pushing for the PM to resign to “forget it” and dismissed writing letters against him as a “sideshow”.

Nadine Dorries, the Culture Secretary, claimed efforts to topple Johnson were being co-ordinated by “one or two individuals” while the “overwhelming number of Conservative MPs are fully behind the PM, absolutely back him”.

Ultra-loyalist Jacob Rees-Mogg described Johnson as an “enormous electoral asset” – despite his latest approval rating in Scotland hitting a new low of -71.

The Brexit Opportunities Minister said: “The idea a change of leader would help the Conservatives is for the birds. It would be the most divisive thing the party could do. It’s an exceptionally silly thing to want to try and open the door to Sir Keir Starmer, assuming he manages to survive.”

Yet the shadow of mistrust hangs over Johnson. In his Mumsnet encounter, the PM had to face the indignity of having to deny he was an “habitual liar”.

And yesterday Lord Evans, chairman of the independent Committee on Standards in Public Life, suggested questions must been raised over whether Downing St upheld proper standards during Partygate.

He said it was up to Lord Geidt, the PM’s ethics adviser, who made a similar point, “to make up his mind on where he goes with this next”. Sources have suggested he is considering his position.

Yet in all this, Johnson’s saviour may not be a wave of unbridled support from colleagues but an absence of agreement on who should replace him. None of the alternative leaders is setting the heather on fire.

The sense of deep Tory unease has not been helped by a string of opinion polls. One this week gave Labour an 11-point lead, another suggested nearly 60% of voters thought Johnson should resign over Partygate, including 27% of Tory voters, while a third forecast the governing party would lose virtually every battleground seat. Conservative minds are being royally focused.

As it stands, it seems either before the June 23 by-elections or after them, a confidence vote is increasingly likely. However, the bar is very high to ditch Johnson. He will take a win, even if it’s by one vote, but, amid the continuing turmoil, the writing will be on the wall for the Conservatives; nowhere more so than in Scotland.