By Ian Dunt

Here's a quick summary of where all 13 Conservative leadership candidates stand on the Brexit issue. Or at least, it's the best we can piece together, given many of them are unclear and others seem to want to avoid the discussion altogether.

This article will be regularly updated as they develop their positions and as candidates either enter or fall out of the race. Candidates are listed in alphabetical order.

The key issues distinguishing them are:

A further extension of Article 50

This is the area where the demands of the campaign are most at odds with what the candidates will face after it is over. The majority of them wish to renegotiate the deal with Brussels, which would take time. They would then have to get that deal passed by parliament, which would also take time. Even if they succeed in both those endeavours, which is frankly unlikely, it's near-impossible to see them doing so within the three month period available between the end of the contest and the October 31st Article 50 deadline.

Even those candidates promoting no-deal have issues with the timetable. There are several pieces of legislation they need to pass before Britain left with no-deal, including bills on agriculture, fisheries, financial services, trade and immigration. The government could try and leave without passing these bills and then use various work-arounds to make up for them, but it's far from clear if this would work. It would also deprive government departments of time to fully prepare for the cliff-edge.

No-deal

The candidates are split into three camps on no-deal: Those who rule it out, those who say they prefer a deal but are prepared to countenance it (no-deal is better than a bad deal), and those are actively aiming for it.

There is a secondary debate about what would happen if parliament legislated to prevent no-deal, as it did earlier this year. Some candidates have come close to saying they would ignore parliament in this scenario, others have been clear they would follow its instructions, others have avoided the issue altogether.

Alternative arrangements

Most candidates are relying on alternative arrangements for the Irish border to replace the backstop. They face serious difficulties with this argument. The first is that the backstop is not a replacement for alternative arrangements, it is an insurance policy against their failure. It triggers if those alternative arrangements fail to guarantee an open border. The EU is therefore very unlikely to give way on this point. And even if it did, it won't agree to the specific arrangements within the three month window.

Some candidates go a step further, calling for the alternative arrangements to be not just agreed but also installed in time for October 31st. They obviously face an even more difficult argument, because there is no agreement on what those arrangements would be, how they would be organised or the technology and infrastructure required to initiate them. Simply put, it would be impossible to achieve in this time frame, if indeed it can be done at all.

Some candidates have accepted that no alternative arrangements can be agreed or implemented before the October 31st deadline.

A second referendum

So far only one candidate has come out in support of this option.

Michael Gove

Extension: Yes

No-deal: Not clear

Alternative arrangements: Yes

Second referendum: Not clear

The former Leave campaigner is prepared to request an extension of Article 50. Initial reoprts suggested this could be until the end of 2020, but his comments at a Spectator hustings suggested it would be moe modest. "If we are making progress and are on the verge of a deal, and we've had a good EU Council in October and we’re 99% of the way there on Halloween, are we seriously saying we wouldn't take a bit more time to get the deal done?" he said. He believes a no-deal Brexit could lead to a general election and put Jeremy Corbyn in No.10, but insists he'd still pick it over no Brexit. The environment secretary is another 'althernative arrangements' fan and intends to appoint a dedicated minister to deliver it.

Sam Gyimah

Extension: Not clear, probably yes

No-deal: Not clear, probably no

Alternative arrangements: Not clear

Second referendum: Yes

The former universities minister is the only candidate currently pushing for a People's Vote. His plan is for two votes, one on Leave versus Remain and then another on deal versus no-deal.

A two-stage referendum is quite a rare proposition in Remain circles, where the debate over whether or not to include no-deal on the ballot paper has influential advocates on both sides. Gyimah's solution manages to partially sidestep that division, but critics worry that it would lead to a no-deal outcome by constantly pitting vague, and therefore more attractive, options next to concrete realities.

Matt Hancock

Extension: Not clear

No-deal: No

Alternative arrangements: Not clear

Second referendum: No

As things stand, the health secretary has the most detailed Brexit plan of all the candidates. He has ruled out no-deal, but he's neither a Remainer nor a Soft Brexiter. He seems committed to the UK leaving the EU on October 31st and rejects the idea that the UK should stay in the single market or customs union.

That leaves him backing a "comprehensive free trade agreement" as the final destination. Although the details may be different in ways he has not specified, this was also May's final destination. Like May, he also wants to seek a time limit to the backstop. When she tried to secure this, she failed. Hancock wants to explore using "an addendum to the withdrawal agreement", rather than re-opening it, another option already explored by May. There is no reason to think he would have any greater success than she had.

In some areas there are changes, however. He wants to set up an Irish Border Council to explore "administrative, political and technological solutions" to combining an independent trade policy with an open border. He also wants to sweeten the pill with payments of £1bn for people on both sides of the Irish border.

The greatest change is really a change in tone and emphasis. Hancock insists that any Irish solution must have the "consent of border communities", which is a change from the more detached approach of many Westminster figures to the Irish situation. He is open about the fact that Brexit involves a series of trade-offs.

Mark Harper

Extension: Yes

No-deal: Yes, but not preferred outcome

Alternative arrangements: Not clear

Second referendum: No

The latest entrant to the leadership contest is prepared to allow for a "short, focused" extension on the October 31st deadline. He insists, like many other candidates, that he would prefer a deal but that he would be prepared to leave without one if necessary.

The short extension he envisages would be to create some time to negotiate and pass a deal through the Commons. "My view is that if you are going to try and get a deal with the European Union and get it through parliament that is not going to be possible by October 31, which means we will need an extension," he said. "I just simply don’t think it's possible to get a deal done and get it through parliament by October 31 because parliament will not be sitting during the summer." Harper seems to be positioning himself as a pragmatic hardliner.

Jeremy Hunt

Extension: Unclear

No-deal: Yes, but not preferred outcome

Alternative arrangements: Not clear

Second referendum: Not clear

In a way the foreign secretary's Brexit pitch is the hardest to describe. There is nothing in it that distinguishes it from May's efforts. He will not rule out no-deal "in extremis", but says he wants a deal. He wants that deal to involve changes to the backstop and "proper guarantees to the legitimate concerns of the government of Ireland". The only distinction seems to be that there would be a change of personnel in the negotiating team to give the Europeans confidence the British side could get a majority in the House of Commons. To put it at its kindest, it's not clear that replacing May for Hunt would have that effect. He also wants a change of tone in negotiations, saying "if we go to Brussels with a very hardline approach we will get a very hardline response".

Sajid Javid

Extension: No, but would accept if parliament voted for it

No-deal: Yes, but not preferred outcome

Alternative arrangements: Yes

Second referendum: No

The home secretary plans to use 'alternative arrangements' to replace the backstop. He is offering a "grand gesture" to Ireland of paying the upfront and running costs for the technology.

In one sense he is striking a more moderate pose than some contenders. For instance, he has admitted that, while he would not actively seek for a further Article 50 extension, he would request it if parliament forced him to. "We are a parliamentary democracy and what we've seen in the last few months is parliament has taken on some extraordinary powers to initiate its own legislation. So if it's statute, if it's the law, I would not break the law if I was prime minister, of course I would observe the law."

On the other he is still very hardline on Brexit. He has said that he rules out revocation, another referendum or an early general election. He insists he is committed to no-deal over no-Brexit and plans to ramp up preparation for it, including through an emergency Budget.

Boris Johnson

Extension: No

No-deal: Yes, but probably not preferred outcome

Alternative arrangements: Unclear, probably yes

Second referendum: Unclear, probably no

The former foreign secretary and leadership frontrunner has said almost nothing about Brexit. His only meaningful statement during the leadership campaign was: "If I get in we'll come out, deal or no deal, on October 31." So he has ruled out any extension past that date. He is also expected to try to renegotiate the deal before that date. During a closed session in front of the One Nation caucus of MPs, Johnson reportedly confirmed he would try to negotiate alternative arrangements and ruled out another referendum. However, because this meeting was conducted away from the press, we can't fully confirm those positions yet.

Andrea Leadsom

Extension: No

No-deal: Yes

Alternative arrangements: No

Second referendum: No

The former Commons leader, whose resignation triggered May's departure, has the most hardline Brexit position of all. She is not prepared to even try and renegotiate the existing deal. "The withdrawal agreement bill is dead - the EU won't reopen the withdrawal agreement and the UK parliament won't vote for it," she said. She is not prepared to extend Article 50 either, or hold a second referendum or general election this year, or form an alliance with the Brexit party.

That leaves no-deal as the only option. Leadsom's plan for delivering this is very confusing. First, she intends to use legislation in Westminster to try to control issues in Europe, such as the status of Brits on the continent or information-sharing with the EU. Domestic legislation cannot have that effect unless there was some sort of deal to secure it with the Europeans, so it's unclear what she means by this or even if she understands that it would not be effective.

Second, she plans to negotiate a series of mini-deals with Europe for particular sectors, including highly sensitive matters like regulations. "What I’m suggesting is making an offer to the EU for things that were already agreed in the withdrawal agreement," she said. "That will enable us to leave with a managed exit." This idea has been repeatedly ruled out by EU negotiator Michel Barnier. It was no empty threat either. When the EU did eventually publish its no-deal plans they were unilateral initiatives.

Leadsom also suggested she would try to hold talks with individual European member states directly. The British government tried repeatedly from the start of Brexit talks to divide member states along these lines, to no effect.

Esther McVey

Extension: No

No-deal: Yes

Alternative arrangements: No

Second referendum: No

The former welfare secretary hasn't quite ruled out renegotiations with the EU, but seems largely uninterested in it. Instead, she is fixing her attention on no-deal. She has ruled out any further extension of Article 50.

Her comments on no-deal are confusing. Firstly, she insists "we can do an invisible border" by October 31st, using technology which "already exists". While some experts believe an open customs border could be created, none believe it could be accomplished in three months. The new customs declaration system, for instance, has taken several years to introduce. She also claimed "the EU ain't going to put up a border", even though it has stated there will be a border in the event of no-deal and issued instruction to member states to initiate normal requirements for customs and regulations checks for third parties.

Dominic Raab

Extension: No

No-deal: Yes, but not preferred outcome

Alternative arrangements: Yes

Second referendum: No

The former Brexit secretary has a fairly standard approach to the issue. He will try to renegotiate the backstop and replace it with the alternative arrangements in the so-called Malthouse Compromise. He wants a 'best in class' free trade agreement as the final outcome and rules out a customs union. He is prepared to leave with no-deal.

Raab's pitch appears to involve being even more hardline than Johnson. He has said that he would prorogue parliament if it tried to stop no-deal - ending the session so MPs could not vote to prevent it. This is an extremely serious argument. It would involve ending parliamentary scrutiny on a crucial political decision with no electoral mandate and politicise the queen.

Rory Stewart

Extension: Unclear, probably yes

No-deal: No

Alternative arrangements: No

Second referendum: Unclear, probably no

The international development secretary has impressed many centrist voters with his moderate views, Brexit realism, and energetic campaigning. He rejects no-deal or serving in a Cabinet which was trying to deliver it. He also accepts that the 'alternative arrangements' favoured by many of the other contenders will not be accepted by Brussels in the months before October 31st.

Instead he wants a citizens assembly put together to try to work out a solution to Brexit, with their findings then recommended to parliament. Apart from this, it is still not quite clear what his approach would be. Some of his statements suggest he supports membership of the single market. But other interviews, for instance this one, see him emphasise "a trade deal with zero tariffs", which is no different to May's final destination.

Ian Dunt is editor of Politics.co.uk and the author of Brexit: What The Hell Happens Now?

The opinions in Politics.co.uk's Comment and Analysis section are those of the author and are no reflection of the views of the website or its owners.