After six years of fraught negotiations, it looks increasingly likely that UK researchers will lose access to European Union research funding because of Brexit.

The crushing loss would be leaving the EU’s flagship research programme Horizon Europe, which over seven years will disburse nearly €100 billion (US$101 billion) in research funds. The UK government says that it has a back-up funding plan for researchers — called Plan B — but details are lacking, and the UK government is in turmoil after dozens of ministers resigned, forcing Prime Minister Boris Johnson to step down (Johnson has said that he will stay in the post until a successor is appointed).

In recent weeks, the European Commission (EC) has cancelled grants won by UK researchers, and the United Kingdom has set a negotiation deadline of summer’s end. The failure to reach an agreement over Horizon Europe membership is the result of political differences between the United Kingdom and the EU over Northern Ireland.

With the writing now on the wall, UK-based scientists are looking for answers about what will replace the prestigious schemes that they could lose access to.

Nature looks at what’s known about Plan B.

Why is the United Kingdom in this position?

Since the country voted to leave the EU in 2016, its scientists have worried about the potential loss of EU research funds, a crucial income stream. Horizon Europe, which will run until 2027, includes the prestigious European Research Council (ERC), which awards unrivalled fellowships for basic research.

In 2020, a Brexit trade deal made between the United Kingdom and the EU included provisions for the United Kingdom to become an ‘associate’ member of Horizon Europe, which would give UK-based researchers most of the same rights to funding as scientists in EU nations. But, despite 18 months of talks on association, no deal has been inked.

Why is this coming to a head now?

Negotiations have stalled over a disagreement on how to implement a border between the Republic of Ireland, which is part of the EU, and Northern Ireland, which is part of the United Kingdom. During the negotiations, however, UK scientists were encouraged to continue bidding for EU funding in the hope that a deal would be made and funds paid.

Now, the EU has cancelled the grants of some UK scientists who had won Horizon Europe funding. Almost 150 UK-based researchers won ERC fellowships in the council’s first funding call, but the EU has now said that UK researchers can take up the grants only if they transfer to an institution in an EU member country. So far, 18 scholars have opted to do so; a further 8 are waiting for transfers to be approved. The ERC has cancelled the grants of 115 successful applicants and a further 6 awardees have asked for more time to make a decision because of extenuating circumstances.

The ERC told Nature that it expects the number of UK-based applicants losing funds to rise, because it is offering the funds from cancelled grants to applicants on a reserve list — some of whom are in the United Kingdom. They will be able to take up the grants only if they relocate.

The United Kingdom has now put pressure on the EC to make a deal. Last month, the then UK science minister George Freeman, who resigned last week during the effort to force Johnson to quit, said that he would give the commission until September to make a deal. Without one, the United Kingdom would enact an alternative research-funding mechanism, known as Plan B.

What is Plan B?

Plan B is the UK government’s alternative to associating with Horizon Europe (which has always been the first choice, or Plan A). Ministers have been seriously considering an alternative to association since 2019. A report that year called for the creation of a flagship fellowship programme to rival the ERC’s, as well as a suite of international fellowships to lure talent from overseas and a boost to basic-research funding.

Last month, Freeman gave evidence to a parliamentary science committee about how the plan is shaping up. He described a four-pillar programme that included a “very strong talent piece” that would offer fellowships and international fellowships. A second pillar, combining industry and innovation, would provide a “bold offer” to break the cycle of short-term funding; he described this as “a DARPA-style, Wellcome Trust-style, Max Planck-style funding mechanism”.

A third global pillar would look to “deepen our multilateral and bilateral work across the world to tackle global challenges”. A final pillar would cover major investments in infrastructure.

Plan A is still the best outcome for UK scientists, but it’s right that the government is making alternative plans, says Stephanie Smith, head of research policy at the Russell Group of UK research universities. “We are now at a stage where it’s time the details were published so the UK research community can make the most of Plan B if it is required,” she adds. “We would need an exciting and compelling offer on talent, on innovation and global partnerships to ensure we can deliver on ambitions to maintain and strengthen the UK’s position as a science superpower.”

Who would be in charge of Plan B?

This is not yet clear. The central research funder UK Research and Innovation (UKRI) could be an option. It already disburses around £8 billion (US$9.5 billion) of research funding annually (UKRI declined Nature’s request to comment on Plan B). The government ministry responsible for science — the Department for Business, Energy & Industrial Strategy — said that details of its “immediate plans” will be published shortly.

News reports have suggested that the UK government has approached the country’s four national academies to run fellowship schemes, but that no decision has been made. The academies — the Royal Academy of Engineering, the Royal Society, the Academy of Medical Sciences and the British Academy — declined Nature’s request for comment on specific plans.

A Royal Society spokesperson said that the society has contributed to the government’s contingency planning on research funding, but that its position remains that association with Horizon Europe is the best option for UK science.

Where’s the money coming from?

In 2021, the UK Treasury put aside £6.9 billion to foot the bill of associating with Horizon Europe and other EU science programmes, or to fund any domestic alternative, until 2024–25. Speaking to the science committee in June, Freeman said that negotiations with the treasury about how to allocate the funding for such a scheme were ongoing.