Nearly two years after Britons voted to leave the European Union , Brexit’s impact on European science is finally coming into focus.

Last week, Prime Minister Theresa May announced that the United Kingdom wants to take part in the next EU research-funding programme , set to be worth almost €100 billion (US$116 billion). Days later a government document released on 23 May provided the most specific details so far about the country’s hopes for a European science deal. Meanwhile, the European Commission (EC) is expected soon to issue rules for international participation in the framework programme, called Horizon Europe, which might apply to the United Kingdom.

Nature examines what these developments mean for UK and EU science after Brexit.

What does the United Kingdom want?

Britain is willing to pay for access to Horizon Europe, which will begin in 2021, after the country leaves the EU on 29 March 2019. But it wants to have an “appropriate level of influence on the shape of the programme” in line with its financial contribution, according to the 23 May document.

Can non-EU countries take part in the current research funding programme?

Yes. Scientists from any country can take part in the current Horizon 2020 scheme, for instance, as collaborators on grants. But only scientists in some non-EU countries are able to bid for grants. The bulk of these applications come from researchers in ‘associated countries’ whose governments pay a fee to the EC to take part. Switzerland, Norway, Israel and Turkey are examples of associated countries.

There are rules about which countries can associate with Horizon 2020. Under current participation rules, the United Kingdom would not qualify after Brexit. Countries have to be a member of the European Free Trade Area, or a member of the European Neighbourhood Policy (which covers countries to the south or east of Europe such as Tunisia and Israel), or be attempting the join the EU. It is not clear whether Britain will seek to rejoin EFTA after Brexit.

Rules about the next funding programme and who can join it are being drawn up in Brussels. They are expected to include measures that will allow more non-EU countries to take part. A rule change would be “the perfect entry route for the UK”, says Kurt Deketelaere, the president of the League of European Research Universities based in Leuven, Belgium.

So the EU may open up the next programme to the rest of the world?

It is thought so, yes. Behind closed doors bureaucrats are discussing how to boost the number of international scientists involved in the programme, according to Deketelaere. International participation in Horizon 2020 dropped compared with the previous funding scheme, in part because the EC changed the funding rules for some countries with emerging economies, such as Brazil, Russia, India, China and Mexico.

The EC’s commissioner for research, science and innovation, Carlos Moedas, has also made open science his mission. As part of this push, he wants European research to be “open to the world” and to enable partnerships between regions and countries. An independent high-level group that looked at how to boost EU science recommended that the EC open up association to other countries on the basis of excellence. It specifically mentioned Canada and Australia.

Thomas Jørgensen, a senior policy coordinator at the European University Association in Brussels, says it looks likely that a new kind of association agreement might be put in place for countries that do not meet the current requirements.

A report by The Guardian newspaper, which claims to have seen a draft of the revised participation rules, suggests that countries using the new association policy might have to pay a relatively high price to join the scheme and might not be able to access all parts of the funding programme.

Do other countries want to join?

Other than the United Kingdom, it is not yet clear whether any non-EU countries want to become associated with the next programme that are not already, or how much it could cost them.

Do current associated countries have the kind of influence the United Kingdom seeks?

Currently, only EU member states can vote on the budget or final regulations of any future EU research programmes. Deketelaere says that this is unlikely to change. Associated countries can informally influence the discussions about the framework programme in various ways, such as putting forward people to sit on expert advisory groups, for example. “The big question is whether there is a privileged position for the UK,” says Jørgensen.

When will we find out more?

On 7 June, when the EC is slated to release a document that gives further information about the next funding programme. This Horizon Europe document is likely to outline the priorities and structure of the scheme, and it looks likely to include new rules that allow non-EU countries such as the United Kingdom to join it.