LONDON — The race to be the U.K.'s next prime minister is in full swing and despite candidates' attempts to present a wide array of policy ideas, there's only one issue that's going to define the contest: Brexit.

Key to each candidate's chance of success with a heavily Euroskeptic party membership will be their attitude to a clean-break, no-deal Brexit. However, many Tory MPs, who will choose the final two to fight it out in the members' ballot, will also be looking for somebody who can find a compromise approach that stands a chance of uniting the party after the endless in-fighting during Theresa May's premiership.

Few of the candidates appear to have taken seriously EU warnings that May's Withdrawal Agreement cannot be renegotiated, and only one of them is advocating a second referendum or Remain position. But there are still significant differences in their stances, broadly splitting them into two camps: Brexit true-believers who are prepared to go for no deal on October 31, and compromisers seeking an unlikely renegotiation.

Here's where they all stand on Brexit:

Michael Gove

How they voted: Leave

Deal or no deal? Has yet to clearly state his current stance but has not pulled his punches in the past about how damaging he thinks a no-deal Brexit would be, to the U.K.’s farming sector in particular. The Telegraph cited an anonymous source as saying Gove has told colleagues that leaving without a deal on October 31 is not feasible and he is prepared to delay Brexit until the end of 2020.

Prior Brexit experience: Was a leading light in the Vote Leave campaign, put forward to contest some of the key TV debates and was seen as a safer pair of hands than Boris Johnson, if not as much of a crowd-pleaser. Was relegated to the backbenches by Theresa May in 2016 but returned as environment secretary in 2017, promising a “green Brexit.” His Brexiteer credentials, combined with this agenda and his reluctance to embrace no deal, have seen him billed as a unity candidate for the party. He backed May’s deal and continues to serve in the Cabinet.

Key quote: "Let no one be in any doubt how difficult and damaging [no deal] would be for British farming," he told the National Farmers Union conference in February.

Brexit believer rating: 4/5

Sam Gyimah

How they voted: Remain

Deal or no deal: The most pro-EU candidate in the contest by far. Says he entered the contest to "broaden the race" and wants to represent the "broad sweep of opinion" in the U.K. on how to deal with Brexit. If he wins, he has promised to legislate for a second referendum with Remain, no-deal and Theresa May's deal on the ballot paper.

Prior Brexit experience: Not much. Was a government aide to David Cameron when he was prime minister. Subsequently held a string of junior ministerial posts, culminating in a stint as universities and science minister. He resigned from that position in November in protest at May's Brexit deal.

Key quote: "My plan will be a new referendum with a new set of questions — to bring us together and solve the impasse," he said on Twitter.

Brexit believer rating: 1/5

Matt Hancock

How they voted: Remain

Deal or no deal? Has set out the most detailed plan for how he would handle Brexit of any of the candidates, in a letter to Tory MPs. He says MPs will never allow a no-deal outcome, and therefore wants to get something like the existing deal through parliament. Acknowledges that the EU is unlikely to reopen the negotiation on the Withdrawal Agreement (Hancock says any candidates who says they can "is not being straight with you".) Has ruled out going for a general election before delivering Brexit because it would risk a Conservative defeat and Labour's Jeremy Corbyn as prime minister. And said that MPs could be persuaded to back a deal if the government focuses on “alternative arrangements” to the backstop but has not been clear about what this would mean. He has ruled out going for a second referendum.

Prior Brexit experience: As health secretary in Theresa May’s Cabinet, Hancock has had responsibility for preparing the National Health Service for Brexit, most notably via contingency plans to ensure the supply of medicines in the event of no deal. He backed May’s deal and continues to serve in the Cabinet.

Key quote: “We’ve got to be brutally honest about the trade-offs … required to get a deal through this parliament,” he told BBC Radio 4.

Brexit believer rating: 2/5

Mark Harper

How they voted: Remain

Deal or no deal? Wants to leave with a deal, but if a deal that satisfies MPs is not possible then the country should leave with no deal. He told Sky News that leaving with a deal on October 31 is not a "credible promise" and it could be necessary to renegotiate the deal with Brussels. His main pitch is that he is a clean pair of hands who has been out of government during the May era.

Prior Brexit experience: None. But he held various junior ministerial posts in David Cameron's government culminating in a stint as chief whip.

Key quote: "I don't think we should take the people who were responsible for where we got to now and assume they've got the solutions for how we move forward," he told Sky News.

Brexit believer rating: 3/5

Jeremy Hunt

How they voted: Remain

Deal or no deal: Has come out firmly against no deal, saying on Tuesday that to go for it would be “political suicide” for the Tory Party. Wants to renegotiate May’s deal, chiefly the backstop, with a new team including Brexiteer MPs and has cited the role that technology could play to prevent a hard border on the island of Ireland. Believes that going for no deal would lead to parliament bringing down the government. That would trigger a general election that Labour might win.

Prior Brexit experience: Has served as foreign secretary for nearly a year, in which time he has done his bit for Brexit diplomacy (not always successfully). Is one of a small number of senior ex-Remainers to say they have some regrets about the way they voted. Backed May’s deal and continues to serve in the Cabinet.

Key quote: “Trying to deliver no deal through a general election is not a solution; it is political suicide. That would delight Nigel Farage and probably put Jeremy Corbyn in No. 10 by Christmas,” he wrote in the Telegraph.

Brexit believer rating: 2/5

Sajid Javid

How they voted: Remain

Deal or no deal? Says that the Northern Ireland border has been the "tail that wags the dog" and pledged to focus on negotiating changes to the Irish backstop. In a BBC interview he pledged to build "good will" with Dublin by offering a "grand gesture" to pay for the upfront and running costs of what he called a "digitized border." In February he insisted that the U.K.’s security would not be seriously affected while acknowledging a “change in capability” in terms of access to EU databases.

Prior Brexit experience: As home secretary, Javid played a role in Brexit contingency planning and preparing for the post-Brexit immigration system. He backed May’s deal and continues to serve in the Cabinet.

Key quote: "I will focus on the one Brexit deal that has already got through Parliament — that was the withdrawal agreement with a change to the backstop," he told the BBC's Andrew Marr show.

Brexit believer rating: 2/5

Boris Johnson

How they voted: Leave

Deal or no deal? Has been clear that no deal is very much an option, and that the U.K. will leave on October 31 one way or another. Aides say he will seek to renegotiate May’s deal, specifically to ensure that the backstop will not be indefinite. Despite becoming, for many, the face of Brexit, some Tory MPs consider him more likely to compromise than some of the other Brexiteer candidates.

Prior Brexit experience: Was the figurehead of the Vote Leave campaign, but pulled out of the 2016 leadership race before it had formally begun. He was appointed foreign secretary by May after she took office and served for two years before resigning in protest at her “Chequers” proposals for the post-Brexit relationship with the EU. Voted against May’s deal twice before backing it at the third time of asking.

Key quote: “No one sensible would aim exclusively for a no-deal outcome. No one responsible would take no-deal off the table,” he wrote in the Telegraph.

Brexit believer rating: 4/5

Andrea Leadsom

How they voted: Leave

Deal or no deal? No deal is not Leadsom’s first priority, but she has insisted that it would be “not nearly as grim as many would advocate.” She has emphasized the depth of civil service preparations for the scenario. Like Johnson, she sees October 31 as a final date by which the U.K. must leave the EU, but has pledged to put “significant effort” into securing a deal that parliament could accept before then.

Prior Brexit experience: Was another leading figure in the Vote Leave campaign, and served in May’s Cabinet from the beginning, first as environment secretary, then as leader of the House of Commons. She resigned from that post just two days before May announced her own departure.

Key quote: “I think any policy needs to be that [October 31] is the date of our departure,” she told the Sunday Times.

Brexit believer rating: 5/5

Esther McVey

How they voted: Leave

Deal or no deal? McVey's statements on the prospect of no deal have been the most bullish of the candidates. She has ruled out any more extensions, pledged to prepare the country for no deal and will only renegotiate the deal if the EU approaches the U.K. first.

Prior Brexit experience: McVey served in the Cabinet as work and pensions secretary from January 2018 until November that same year, when she quit in protest at May’s Withdrawal Agreement.

Key quote: “If they want to have a better deal that’s fine, we’ve always wanted a free-trade agreement but what we’ve got to do is not waste time, time is limited, we have to make sure that we are ready to leave," she told Sky News.

Brexit believer rating: 5/5

Dominic Raab

How they voted: Leave

Deal or no deal? Has rejected suggestions from Hunt and Hancock that going for no deal would lead to a general election and refused to rule out, in an interview with the Spectator, proroguing parliament (i.e. suspending the legislature) to get no-deal through. He has said he would fight for a “fairer” Brexit deal but will leave without one in October if unsuccessful.

Prior Brexit experience: Had a short spell as Brexit secretary from July 2018 until November 2018 when he quit in protest at May’s Withdrawal Agreement.

Key quote: "I’ll fight for a fairer deal in Brussels, with negotiation to change the backstop arrangements, and if not I will be clear we’d leave on [World Trade Organization] terms in October,” he told the BBC’s "Andrew Marr Show."

Brexit believer rating: 5/5

Rory Stewart

How they voted: Remain

Deal or no deal? Has been scathing about proponents of a no-deal exit, describing WTO terms as “the worst possible … the terms that Afghanistan has been trading on,” in an uncompromising interview with PoliticsJOE. He also agrees with Hunt and Hancock that no deal would not be approved by parliament. Wants to deliver Brexit “as quickly as possible” but with a deal, delivered via a citizens’ assembly, and believes a second referendum would likely be divisive.

Prior Brexit experience: Had kept his hands relatively clean of Brexit until the leadership contest, serving as a junior minister in May’s government until May this year when he was appointed international development secretary.

Key quote: “You need a Brexit deal to last for 40 years — the danger of revoke or no deal is that you end up in a very unstable situation,” he told the Guardian.

Brexit believer rating: 2/5

Other candidates

Two candidates from the Brexiteer wing of the party, Kit Malthouse and James Cleverly, have already dropped out of the race.