London; Boris Johnson is launching a bid to court One Nation Conservative MPs in the group of centrist liberals run by Amber Rudd, as he tries to pitch himself as a candidate who can appeal beyond rightwing Brexit supporters.

The former foreign secretary, who is favourite to be the next Conservative leader, is backed by Brexit hardliner Jacob Rees-Mogg but infuriated many Tory colleagues by backing Theresa May’s deal after months of campaigning against it.

Some Conservative MPs have privately threatened to quit the party if Johnson becomes prime minister, with particular anger over his use of populist rhetoric suggesting that Muslim women wearing burqas resemble bank robbers and “choose to go around looking like letterboxes” .

However, Johnson has been making an effort to reach out to the more centrist wing of the party in recent days, endorsing a mini-manifesto released by Rudd’s group of 60 One Nation MPs, which promotes human rights and social responsibility.

The ERG hardcore

The most resistant segment of the European Research Group of Eurosceptic Tory MPs comprises 28 pro-Brexit backbenchers who have refused to be wooed by Theresa May and opposed her third attempt to pass her Brexit deal. Steve Baker, Andrew Bridgen and Mark Francois are the most vocal members. Jacob Rees-Mogg remains close to the group despite backing May’s deal. Another 100 MPs have been associated with the ERG, including the potential Tory leadership candidates Boris Johnson, Michael Gove and Andrea Leadsom.

Blue-collar Conservatives

Esther McVey, a Brexiter who reluctantly voted for Theresa May’s deal, is the latest Tory to breathe life into the idea of blue-collar conservatism, previously championed by Robert Halfon, the chair of the education select committee. McVey launched her version on 20 May at an event widely seen as the unofficial start of her leadership bid. She and fellow MPs including Eddie Hughes, Ben Bradley and Scott Mann plan to tour UK pubs to spread their message. McVey’s supporters claim to have up to 40 MPs signed up to the group; other Brexiters claim the figure is less than 20.

One Nation Group

Amber Rudd has spearheaded this pro-remain, anti-no-deal group of MPs, which includes the international development secretary, Rory Stewart, and the former cabinet ministers Nicky Morgan and Damian Green. The group claims to have more than 60 MPs onboard and plans to stand against “narrow nationalism” and division and in favour of internationalism, environmental policies and protecting consumers from corporations and an “over-mighty state”.

Scottish Tories

Led by the hugely popular Ruth Davidson, the leader of the Scottish Tories in Holyrood, and the Scottish secretary, David Mundell, this group’s overtly remain tendencies put them at odds with the likes of the ERG. Among the 13 Scottish Tory MPs and 31 MSPs there is controversy over Boris Johnson, who is a highly divisive figure in Scotland.

Modernists

A loose term nowadays, since the former Cameroons are largely nowhere to be seen. Those flying the flag for a more socially progressive, relatable kind of conservatism include the former education secretary Justine Greening and the health secretary, Matt Hancock, who even set up his own app in an attempt to keep up with the digital age. Both Greening and Hancock want to move on from Brexit so that other issues can be dealt with, but they are split on what that should look like. Greening has promoted a second referendum, while Hancock is urging all Brexiters to get behind May’s deal.

His change of tack has provoked fresh speculation that Rudd could back Johnson, even though she has campaigned against a hard Brexit.

Friends of the work and pensions secretary say she privately dismisses the idea that she will end up supporting Johnson’s leadership bid when asked about it. However, one MP in the One Nation group said it was very plausible that she will be tempted by the possibility of a big job from Johnson and his potential to save her seat at a general election, since she is MP for the marginal constituency of Hastings and Rye - where her 4,796 majority from 2015 was cut to just 346 in 2017.

Rudd has not ruled out running for the leadership herself but is thought likely to end up backing one of the other candidates and bringing her supporters with her.

Another One Nation source said it was certainly possible that Rudd could end up backing a first choice candidate and then pivoting to back Johnson in the last round if he were to be in a runoff with Dominic Raab or Esther McVey, the most rightwing pro-Brexit leadership candidates .

“It’s really not a Stop Boris vehicle, if anything it is more Stop Raab,” the One Nation source said. “But it is not about the person; it is about the policies. There is no chance that all 60 MPs in the group will back the same person but there is a chance all 60 won’t back a certain person and it is far more likely that person will be Raab rather than Boris.

“We’ve got to get the next phase of the Conservative party right. This is the prime minister who will take us into an election in 2020 or 2022 and that will determine how the next 10 years plays out. We want the most well-rounded candidate. If that’s Boris, it’s Boris. If it’s not, it’s not. This vehicle is intended to ensure the party stays relevant to the centre ground.”

Amber Rudd has recently launched a group of moderate Tories under the banner of One Nation group. Photograph: Sean Smith/The Guardian

The success of Johnson as a leadership candidate depends on his ability to woo enough Conservative MPs to put him in the list of a final two candidates who will then be put to the membership. The pro-Brexit, rightwing Conservative membership heavily favours Johnson ahead of other candidates, according to surveys by the ConservativeHome website.

One supporter of Johnson said: “He is a one nation Tory and always has been, and I think many of his colleagues see this.”

They said Johnson was different to Raab who is “very much a rightwinger” on domestic policy. “Everyone can see Boris is on a different place on domestic policy and it is a natural fit for many of them,” they said. “The party has never been as hostile to him as people make out.”

However, while some centrist MPs believe Johnson offers the best chance of winning an election, others are part of a Stop Boris campaign arguing that he is too divisive and hardline on Brexit to be prime minister.

On Tuesday, he was branded an unacceptable candidate to be prime minister by the Conservative minister Margot James, because of his “fuck business” remark when asked about companies’ concerns over Brexit.

James, a business minister and leading member of the One Nation Conservative group, said the comment meant Johnson was not fit for “high public office” as she addressed a Creative England event in London.

Speaking later to the Guardian, she said some of her colleagues promoting Brexit at any cost to business had the “wrong attitude”.

“I don’t think people in the public eye should be using language like that to discuss the concerns of the business community,” she said. “It’s the dismissive attitude to business that’s a problem among some people for whom Brexit is everything.”

Michael Gove

The fortunes of the environment secretary remain hard to predict and opinion is split in the party. His detractors believe he is deeply unpopular with the country and has ruined his reputation for good when he stood against Johnson at the last leadership race. Most MPs were delighted by his performance in the no-confidence vote where he tore into Corbyn. But robust Brexiters dislike the fact he has stayed loyal even in the final days of the crumbling May regime.

Matt Hancock

While the response of many voters to mention of the health secretary is still likely to be ‘Who?’, to some he is starting to have the makings of a from-the-sidelines contender. The former culture secretary is only 40 but has six years of frontbench experience, and is on to his second cabinet post. The longer the race goes on the more he gains ground for the seemingly basic virtues of being apparently competent and broadly similar to a normal human being.

Jeremy Hunt

The nickname ‘Theresa in trousers’ has stuck. Most colleagues speak about his candidacy unenthusiastically and warn about his reputation with the country after having weathered the junior doctors’ strike. He could still succeed by bridging the Brexit-remain divide and attracting colleagues looking for a moderate grown-up, but recently he seemed unable to outline why his brand of Conservatism might appeal to voters.

Sajid Javid

The home secretary is reported to have told Tory MPs he is the only one who can beat Jeremy Corbyn in a general election, but has made less of an impact than first predicted. Several MPs believe that the case of Isis bride Shamima Begum was mishandled and find Javid’s speeches and vision less than inspiring.

Boris Johnson

Still favourite for the top job, Johnson has kept himself out of the messiest Tory warfare in 2019 and has enthusiastic support from younger Brexiter MPs - and the patronage of Jacob Rees-Mogg. His supporters insist no other name on the list can connect with voters in the same way and win a general election. However, his reputation is still severely damaged from his time as foreign secretary and there is a concerted ‘anyone but Boris’ campaign among party colleagues.

Andrea Leadsom

Leadsom has revived her reputation somewhat during her tenure as Commons leader, especially her rounds in the ring with the Speaker, John Bercow. However, few believe she would ever be first choice again among Eurosceptics and a number of her former campaign team have said they will discourage her from running.

Esther McVey

Former cabinet minister McVey has already announced her intention to run. She has the Brexit credentials, having quit as Work and Pensions Secretary in protest at Theresa May’s withdrawal agreement, and claims to already have enough support from fellow MPs to make her bid viable.

Penny Mordaunt

Previously seen as a definite outsider, her promotion from international development secretary to defence after the sacking of Gavin Williamson has significantly bolstered her position. As both a confirmed Brexiter and a social liberal she could unite different camps, but she remains relatively untested.

Dominic Raab

The former Brexit secretary has a loyal fanbase and a professional team, including support from Vote Leave’s ex-comms director Paul Stephenson. MPs are forming the view that the next party leader should be a younger face from a new generation of politicians - which gives Raab the edge over Boris Johnson.

Amber Rudd

While she has not officially ruled herself out, Rudd’s remainer tendencies and slender majority in her Hastings constituency mean the work and pensions secretary is largely being courted for who she might eventually endorse.

Liz Truss

As much for effort as inspiration. The chief secretary to the Treasury has been almost everywhere the last few weeks - including modelling some slightly alarming trousers in the Mail on Sunday - to explain her free market, libertarian philosophy. Everyone knows what she thinks, but this will still perhaps not be enough.

And those not in the running

Among the senior figures not expected to run are Brandon Lewis, the party chairman, Chris Grayling, the transport secretary, and Philip Hammond, the chancellor, who acknowledges that he is not popular enough. Gavin Williamson’s recent sacking after the Huawei leak inquiry will also surely rule him out as an option this time around.

She said another pro-Brexit leadership hopeful had privately been dismissive about businesses’ concerns to her, saying: “Oh, the tech industry is always moaning.”

She said: “That these people should be anywhere near the levers of power is quite worrying.”

Johnson was reported to have made the “fuck business” remark in July last year when asked about industry’s concerns over Brexit at a diplomatic event.

He later refused to deny he had made the comments, acknowledging in the Commons that he may have “expressed scepticism about some of the views of those who profess to speak up for business”.

A source close to Johnson said his remarks on business had been aimed at “business lobby groups sending out anti-Brexit propaganda”, and argued that “you would find it hard to find anyone more devoted to business than he has been and his record particularly in London on businesses both great and small”.