Standing on a stage in the east of England next to an imposing blue “Exit from Brexit” placard, former Liberal Democrat MEP Andrew Duff’s message was not what the audience at the regional party meeting wanted to hear.

Duff, an authority on the European Union and advocate of further integration, had not come to explain how the process of the UK leaving the EU could be reversed. Instead, he poured cold water on the idea.

“Of course I regret its outcome, but I believe now that we’ve got to, as the mantra has it, to respect the outcome of the referendum. And what does that mean: Brexit,” he said on 14th October at the Millennium Centre in Red Lodge, Suffolk.

His stance stunned the audience. The Liberal Democrats were the only major UK party to fight for a second referendum during the June General Election. Many of his colleagues believe not just that the vote was a historic mistake, but that Brexit should and can be stopped. Duff demurs. For him, the referendum outcome was the culmination of a long, awkward partnership between the UK and the EU. Now, it is the time to establish a new one.

That means focusing on achieving a positive outcome from so far stuttering separation talks and then agreeing a new partnership involving extensive cooperation and reshaped economic integration.

“We can’t play at this. We have to get an agreement that is orderly, sincere and fair and which sets up the UK and the 27 to build up a more sustainable and successful partnering of the UK and the EU than we’ve had for a long time,” Duff argued.

This unusual position rests on his interpretation of two issues that have received relatively little attention in a UK debate that has instead focused on the government’s ineptitude.

The first is that with France’s President Emmanuel Macron and EU Commission President Jean-Claude Juncker setting out plans for deeper integration, the UK would fit as badly as ever into the supranational project. It appears highly unlikely that the UK would anytime soon embrace “ever closer union.”

However, Duff goes so far as to say that the UK will only be allowed to reverse the Brexit process if it agrees to do so. “If we pull out of the Article 50 process we won’t go back to things as they were before the referendum,” said Duff, who is a Visiting Fellow at the European Policy Centre. “Toleration of our peculiarity is now at an end. The terms will be federal.”

The second under-discussed issue is that, if the UK is willing, there is the possibility of a future partnership that would soften the blow from leaving the Single Market and provide for cooperation in areas like security, scientific research, and education. This, according to Duff, will come in the form of a wide-ranging association agreement “which will have at its heart a free trade agreement.”

Counter-intuitively, the closest model for this is the EU’s arrangement with Ukraine, which has effectively been granted Single Market participation, but without the freedom of movement of persons.

Although the EU has stressed the importance of maintaining the market’s integrity, it has not ruled out selective economic integration under a single treaty—despite frequent warnings from Remainers that British “cherry-picking” will not be tolerated. And the Ukraine example shows that does not have to come with open borders for workers. What the Union wants to avoid are sector-by-sector deals, such as the large number that Switzerland has negotiated over decades. In Brussels, Duff tells me in a later interview, “people are prepared to accept” a Ukraine-type partnership and be flexible where possible. “There’s no intention to penalise the United Kingdom.”

Key figures like EU Parliament Brexit coordinator Guy Verhofstadt have even endorsed the idea of an association agreement. And other experts agree such a partnership and enhanced trade deal are possible. “If they laid out something that was both deep and comprehensive and recognisably so, without of course referring to Ukraine, the EU side would say “‘let’s discuss this,'” said Michael Emerson, a former EU Ambassador to Russia, who is an authority on the EU-Ukraine deal.

Instead of objections from Brussels, the main impediment to such a solution is the UK government which is divided and using “appallingly ambiguous and contradictory language” about what it wants, said Emerson. “If you want a deep relationship with as frictionless access as possible to EU markets then you cannot avoid going through the chapters of EU law and saying whether you wish to remain in compliance with EU law or not,” he said. Overall, though, he thinks it would be better to remain in the EU. “I am totally against Brexit, and hope it is reversed in time,” he said.

Kenneth Armstrong, an expert on EU law at Cambridge University and the author of Brexit Time, agreed Brussels would be “highly receptive” to an association agreement, as it is a known concept for the EU’s legalistic bureaucracy and avoids an à la carte approach to the Single Market. He also sees the greatest impediment coming from within the UK: he is unclear why the UK hasn’t yet detailed its intentions and sees Conservative hardliners, who want the UK to be free of EU regulations and rulings, as the biggest obstacle to a close partnership.

He also warns that association agreements require the unanimous approval of EU member states, often including domestic ratification—although he suggests there can be some provisional implementation.

With the Article 50 talks slow due to a dispute over the financial settlement and other issues, there is an increasing sense in the UK that Brexit must be reversed or it will end in disaster. Unlike Duff, Armstrong believes the EU would allow the UK to continue membership in the current form, in the unlikely event it tried to stay in the Union.

However, there are signs that the EU is willing to edge talks forward in the coming weeks. The formal green light to discuss the transition period and initiate talks on the future arrangements may then come at a meeting of EU heads of states in December.

As the framework for the new partnership emerges, the parties will be able to refine the financial settlement. Without clarity on the UK’s continued participation in EU projects and agencies it has so far been hard to agree on the accounting for the UK’s commitments. Ultimately, Duff believes the UK will not crash out of the EU with no deal—which would be likely to lead to a major economic shock with trade slowing drastically—as the people in charge of the talks are not, as he puts it, that “crazy.”

Judging from the Liberal Democrats’ meeting in Suffolk, he has work to do to convince others of his arguments. Openly rejecting party policy, Duff went further than simply opposing a fresh plebiscite. “If we campaign for a second referendum on this thing, the party will be putting itself in the extraordinary position of fighting a referendum campaign to accept the Article 50 agreement alongside the Tories and the Labour Party,” Duff said. This final provocation was met with an anguished cry of “Nooo!” from a member of the audience.