After two years of negotiations, the first real glimmers of what Brexit might involve have emerged. On 14 November, the Cabinet, the UK government’s senior decision-making body, backed a draft agreement on the terms of the country’s withdrawal from the European Union.

For science, many of the details that will be most relevant are still to be thrashed out. But the treaty, if approved, offers detail on the future of nuclear regulation in the UK. An accompanying document hints at provisions for some visa-free travel to and from EU countries — encouraging news for researchers who are used to travelling frequently for collaborations and conferences.

The draft deal will now go to a vote in the UK parliament, slated for 7 December.

Hammered out in fraught negotiations with EU officials, the 585-page agreement would allow EU citizens currently living in the UK — including researchers — and their families to claim permanent residence. This should ease fears expressed by many EU nationals resident in the UK, including many scientists, about having to leave their jobs after Brexit.

The draft divorce document does not cover in detail what the UK and EU's future relationship will look like, for example how immigration policy or its membership of European research-funding programmes might change. However, in a statement, Prime Minister Theresa May confirmed that ‘free movement’ between the UK and bloc — something that researchers say has fuelled scientific collaboration — would end.

Those details will be properly addressed as part of a later trade agreement, which, at least formally, will only be determined after 29 March 2019, when the UK leaves the EU and enters a transition period.

A short accompanying document released by the government sets out in brief a framework on which the future UK–EU relationship will be built. The 7-page, bullet-pointed document suggests that the eventual agreement may allow visa-free travel to and from all EU member states for short visits.

It also mentions “science and innovation” as one part of the “basis for cooperation” on which the future agreement would be built.

A final version of this framework must be agreed on before the withdrawal text is signed, said the government in a related explainer .

Uncertainty over nuclear experiment

The withdrawal agreement confirms that the UK will leave the European Atomic Energy Community, Euratom , when it pulls out of the EU. It fleshes out commitments made in a joint statement last December that the UK will be responsible for international nuclear safeguards in its own territory in line with the existing regime overseen by Euratom.

But the document doesn’t address a key concern for some researchers: whether Britain can retain membership to the world’s largest nuclear-fusion experiment, International Thermonuclear Experimental Reactor (ITER), which it currently enjoys through Euratom.

Nor does it give any indication on whether the largely EU-funded Joint European Torus (JET) — a nuclear-fusion facility in Culham, UK, that is a test-bed for ITER — will receive any cash after its current contract expires at the end of this year.

Regulation and customs

One of the most contentious parts of the withdrawal agreement is a ‘backstop’ — related to the isle of Ireland — that would fall into place should the UK and EU fail to reach an agreement that would allow frictionless trade by the end of the transition period, on 31 December 2020.

The backstop would prevent a hard border between the historically linked Republic of Ireland, an EU nation, and Northern Ireland, which is part of the United Kingdom, by keeping the whole of the UK in a customs union with the EU until an agreement can be reached. It also means the UK would be required to align some regulations with EU rules, including on the environment, labour and state aid, for as long as the backstop lasts, even though the country would no longer have any control over determining such rules.

Scientists from both UK industry and academia, which have consistently sought to retain regulatory alignment with the EU, could welcome this, says Sarah Main, director of the London-based Campaign for Science and Engineering. But they may regret the arrangement if the UK can no longer use its research strength and evidence-based approach to influence European regulation, she says. “I think the trick to pull out of the hat will be to have that alignment but to also have continued influence.” It’s unclear whether that will be possible though, she adds.

The backstop would mean accepting EU laws without having a say in shaping them for an unknown amount of time, which will likely make the deal unpalatable to members of parliament who are staunchly pro-Brexit. Both sides must agree to end the backstop, another factor likely to rile members of parliament who support Brexit.

What happens now

The agreement did not win unanimous backing from members of Theresa May’s Cabinet — and she now faces a fight to get it through the UK parliament. It must then go before the European Parliament and garner the approval of a majority of member states.

If the deal passes, for the research community the crucial next step will be to push for an agreement on science as soon as possible, says Beth Thomson, head of UK and EU policy at the London-based biomedical funder the Wellcome Trust. “This could be an important early win for the UK and EU, whose ambitions for science are closely aligned,” she says.

Thomson says this should include a commitment that would allow the UK to participate in the EU’s next major research funding programme — called Horizon Europe and likely to be worth €100 billion — as an associate country. This status, currently held by non-EU nations such as Israel and Norway, allows the countries to host prestigious European Research Council grants. Whether the EU will agree to this remains unclear.

The agreement should also include cooperation on research regulation, including clinical trials and data sharing, and a reciprocal agreement that would support researchers moving smoothly between the UK and EU-countries, she adds.

No-deal option

If UK lawmakers now reject the proposed agreement, the two sides may re-enter negotiations. But that leaves little time reach an agreement and obtain approval by both parliaments before 29 March 2019.

Failure to do so would leave the UK in the position of a no-deal Brexit — a situation feared by many in the research community.

A no-deal “would be very serious” for science and remains a possibility, says Richard Catlow, foreign secretary of the Royal Society in London. The society warned earlier this year that if the UK leaves the EU without a deal in place “it will impact on scientific research immediately and could take years to rebuild.”

The UK would not only instantly lose access to at least three of the major funding streams under the EU’s current Horizon 2020 funding programme, but imports and exports of essential goods — including food, scientific equipment and medicines — would likely be disrupted.