Boris Johnson is way out in front of the Tory leadership race, with more than double the number of Tory MPs set to back him compared to his nearest Brexiteer rivals, his allies have told HuffPost UK.
Johnson is understood to have more than 80 Conservative backbenchers privately signed up - a quarter of the entire parliamentary party.
The former foreign secretary is also on course to win more than twice the support of fellow Leave campaigners Michael Gove and Dominic Raab, according to a highly detailed headcount of all 313 Tory MPs conducted for the Johnson campaign.
However, his campaign is adopting a deliberate strategy of holding back public endorsements in a bid to build daily momentum ahead of the start of the leadership contest next week.
In a carefully coordinated move, a raft of 11 more backbenchers came out to support the former secretary of state on Monday, taking his publicly revealed total to more than 40 MPs.
Theresa May will formally step down as Tory leader on Friday and is expected to be replaced as prime minister by late July.
Johnson formally launched his campaign with a new video showing him meeting voters on the doorstep of Peterborough, where a Westminster by-election is being held this week.
One Johnson ally even said that he was ‘closing in’ on the 105 MPs needed to guarantee his name goes on the final ballot of party members, although his campaign admit a chunk of backbenchers may decide to keep their choice private.
Johnson has former chief whip Gavin Williamson on board, who is using all his detailed knowledge of the parliamentary party to identify sources of support and opposition.
A maximum of 20 MPs have been identified as ‘anyone-but-Boris’ critics, lower than the Johnson team had expected.
Jeremy Hunt, the former Remainer seen as the leading ‘centre-right’ candidate, is currently second in the race, Johnson supporters estimate.
Gove and Raab could end up with around 40 MPs each during the first round of voting. Sajid Javid - who on Monday picked up the backing of Attorney General Jeremy Wright - and Matt Hancock are expected to hover around the 20 mark.
But six contenders - Andrea Leadsom, Rory Stewart, James Cleverly, Kit Malthouse, Mark Harper and Esther McVey - can barely muster double figures for the number of committed supporters they each have, the latest Johnson campaign data suggests.
A total of 13 leadership candidates have announced their intention to run for the top job, and a further four are still weighing up their options, when the MPs’ ballot begins next week. New contender Sam Gyimah appears so far to have no support other than his own name.
The list of candidates will be whittled down to a shortlist of two in a series of votes by Conservative MPs. The final pair then go to a postal ballot of all party members, with the position of leader – and prime minister – going to the victor.
The sheer size of the field prompted some senior party grandees to convene on Monday to discuss raising the current threshold of just two MPs needed for a candidacy.
The officers of the backbench 1922 Committee discussed plans to change party rules to insist on at least 10 or possibly 12 nominations per candidate.
The full executive of the committee is set to debate the issue on Tuesday when the Commons returns from its Whitsun break.
Although Johnson’s rivals still believe he can be beaten once the contest transfers to the party’s 160,000 members at the end of the month, he has built up a formidable profile since quitting May’s Cabinet last year in protest at her Brexit plans.
At least one rival campaign doubted the veracity of Johnson’s figures, with a source saying “Boris was meant to have big numbers in 2016 - look how that ended”.
An ally of Dominic Raab pointed to a YouGov poll showing that he was more popular among Tory voters than both Johnson and Gove.
And Raab supporters are sharing a snapshot study of 200 party members by University of Liverpool academic David Jeffrey that suggested Raab could actually beat Johnson.
Gove’s camp meanwhile is convinced that he will emerge as the main opponent for Johnson. Some of the environment secretary’s supporters believe that he can leapfrog Hunt once Raab is knocked out of the contest, picking up his fellow Leaver’s backers.
One count of publicly declared MPs put Johnson on 41 MPs, Hunt and Gove 28, Raab 23, Javid on 18 and Hancock on 11.
Rory Stewart won the backing of cabinet minister David Gauke at the weekend. His campaign played down suggestions that he was failing to get more than 10 MPs.
“We’ve had a real step up in support - with Rory’s odds of becoming the next leader halving in just two days. Rory secured two major endorsements over the weekend - on top of the others who had already declared - and we will be announcing our other endorsements in the coming days,” a spokesperson said.
A spokesperson for Esther McVey said: “You will be able to see how many MPs are supporting Esther when the time comes.
“We are discussing the issues that matter: a clean Brexit and more money for schools and police by cutting the bloated overseas aid budget. Candidates who are only talking about numbers presumably have no policies to talk about.”
Cleverly told HuffPost: “We’ll deal with whatever rules the 1922 decide upon. Members will want to see all candidates and their ideas tested properly.”
The Telegraph reports that one proposal is for four rounds of voting among MPs, with the final two candidates chosen by Thursday, June 20.