Henry Newman is Director of Open Europe.

By April of next year, the United Kingdom will have left the European Union. Even some of those calling for a second referendum – or what is disingenuously termed a “people’s vote” (as if June 2016 wasn’t just that) – admit in private that they have little hope of actually stopping Brexit. And with three crucial bills now on the statute book and both main parties opposed to any further referendum on the deal, a serious reversal seems pretty far-fetched. The open question is not whether the UK leaves the EU but how it does so.

My view remains that it’s still most likely that both sides reach agreement on withdrawal terms before the end of Article 50. That’s obviously the preferred outcome of both the UK Government and the EU. And, as Michel Barnier has made clear, the withdrawal is already 80 per centt locked down – with sections on citizens’ rights and the UK’s financial contribution largely settled. The outstanding issue is really the Irish border issue, which as I explained previously could still derail an orderly exit.

But although it’s likely, it’s not certain that an agreement will be reached. The EU’s intransigence over the Irish backstop, which is the insurance policy intended to keep the border open, may mean that both sides can’t sign things off. Political divisions in the UK, which have especially come to the fore since Chequers and the subsequent ministerial resignations, underscore the Government’s weak support base in the Commons, raising the possibility of a total deadlock. And under the terms of Article 50 the UK will be out the EU by April, unless both sides agree to extend the negotiations.

October’s European Coucil in Brussels has long been expected to be a crucial point for the negotiations, but the UK is also seeking to use the September informal Coucil meeting held in Salzburg, under the Austrian rotating presidency, to make progress. The Prime Minister remains determined to engage EU leaders personally in the Brexit talks, hopeful that they will intervene to push a deal over the line.

So far the leaders of most EU countries have largely been happy to leave things to the Commission. This is partly because the main issues under discussion so far are ones on which the 27 agree most clearly. As the Polish Foreign Minister told me, every EU member believes the UK should pay as much money as possible for as long as possible. Equally, there’s little division over agreeing the maximum possible protections for the rights of EU citizens in the UK.

Agreeing the terms of the future relationship will be harder. That’s not to say we are certain to see a real breakdown in the EU27’s unified position. But there will be a wider range of views over the right balance of obligations and access to allow the UK. We have already seen in recent weeks significant interventions criticising the EU’s position on Brexit from the interior ministers of both Germany and Italy. When it comes to discussing whether the UK could participate partially or fully in the Single Market for goods, without signing up to free movement, there may be a range of different views.

Meanwhile, the Parliamentary position in the UK is very divided. As some have observed, there’s clearly a majority for Brexit overall in the Commons, but it’s not clear that there’s a majority for any particular Brexit. One group of MPs openly advocate a No Deal exit, while the Opposition stick to the preposterous position that they will vote down the withdrawal agreement if Brexit doesn’t deliver the exact same benefits of membership. [Spoiler alert: this is impossible]. Stuck in the middle is the Government and its Chequers plan. Some MPs would happily vote for a permanent arrangement like Norway’s, others will never vote for a deal which didn’t guarantee the UK total control over migration policy.

Parliament isn’t being asked to vote now on Brexit though. If it was, there would certainly not be a majority to walk away from the negotiations. Things might, however, look different in a few months time. MPs may feel that the Government has tried to offer reasonable comprises to the EU, including at Chequers, but they have been rejected in favour of unreasonable demands. The Commons was unanimous in rejecting a customs border in the Irish Sea – between Northern Ireland and Great Britain. Yet that is precisely what the EU is demanding. There may not be a way through.

If there’s no real breakthrough by the late autumn the chances of No Deal will be very high. But even if there’s no agreement on the withdrawal treaty, the UK and EU could tie off some discreet deals to avoid the maximum disruption of an acrimonious exit. For example, both sides would have a big incentive to agree a new framework for aviation, whatever happens.

So although the new Foreign Secretary is right to warn that a total collapse in negotiations would have hugely damaging effects including for diplomatic, security and defence cooperation across the continent, it remains less likely a prospect than Liam Fox suggested in Sunday’s intervention, when the Trade Secretary put the chance of No Deal at 60 per cent. Still, Whitehall must be prepared for every eventuality – including both a ‘negotiated’ No Deal and an acrimonious one. Open Europe will soon be producing key recommendations for the Government to enact in the event of such a breakdown in negotiations

Meanwhile, it’s not certain we will know the shape of our future relationship with the EU by the time Parliament is asked to vote on Brexit. EU diplomats tell me that in her private meetings the Prime Minister has been pushing European leaders to agree the greatest possible detail on our future relations with the EU, before the end of Article 50. Her view is that MPs will be reluctant to sign off on any payment to the EU without a clear idea of what they’re getting in return. Perhaps.

It’s also possible that both sides prefer to fudge things to get the deal over the line. That will mean that what the Prime Minister used to call the “implementation period” is when almost all the detail of our future relations gets locked down, assuming agreement can be found on that by 2021. So overall although it’s almost certain that the UK will leave the UK next spring, the range of possible outcomes for Brexit remains quite wide open.