Prof Chris Gosden, director of the institute of archaeology at Oxford University, is bracing himself for potential disaster after Brexit. Europe funds 38% of archaeological research in the UK and with no plan B, Gosden fears his discipline could dwindle unless an agreement is reached on science.

“Losing EU funding would mean that British archaeology would shrink,” Gosden says. “Our discipline has had a great 50 years. It is really sad to think that in 10 years it could be much smaller.”

The government has guaranteed all research cash awarded in the current €70bn (£62bn) European research programme, Horizon 2020, which funds cutting-edge science. But researchers have no idea what to expect beyond 2020.

When Britain leaves the EU it could pay to be an associate member of the next European research programme, Horizon Europe, which is expected to distribute another €100bn to researchers over seven years. But many academics warn that a hard Brexit, or what one vice-chancellor describes as “a cataclysmic no-deal”, would wrench apart research collaborations with Europe, and UK disciplines could be left with huge holes in funding.

“A lot of academics feel we should have done more to fight this,” says Gosden. “But when you don’t know what’s going on, it’s hard to oppose. We are shuffling around in a fog.”

Gosden’s institute has been awarded 10 major European Research Council grants since 2007, awards prized by academics for their international prestige as well as their monetary value. They allow his researchers to work on a scale that would not be possible otherwise, he says.

He adds that big collaborative research projects take up to two years to plan, and British academics already need to be thinking beyond 2020. “We are all desperately hoping it will sort out, but we haven’t got a plan B,” he says.

Simon Marginson, professor of higher education at Oxford, who is researching the impact of Brexit on universities, thinks the outlook for research is gloomy. “In my judgment we are likely to have a hard Brexit, or at best an unresolved research funding picture. In terms of people in research and higher education, the fallout will be massive.”

He says that stepping up research partnerships outside the EU is not a solution. “In research funding, other countries naturally give priority to their own citizens or residents. That is why the EU research programmes are so valuable. They make decisions on merit across a large number of countries, dramatically widening the potential pool of talent and ideas, and they encourage collaboration.”

Prof Lee Cronin of Glasgow University: ‘Many of us will be forced to move our research abroad.’ Photograph: Murdo MacLeod/The Guardian

Behind the scenes, vice-chancellors are racing to find ways to safeguard European research collaborations. Prof Colin Riordan, of Cardiff University, a member of the prestigious Russell Group, says: “We are doing detailed planning for a no-deal Brexit. It is a massive headache and a huge diversion of time and effort.”

One option is to move academics abroad. Cardiff is considering offering key researchers joint contracts with universities across the Channel, with as much as 80% of their time spent outside the UK, allowing access to European cash. Imperial College London last week announced “double contracts” with the Technical University of Munich, and other Russell Group universities say they may follow suit.

“The bottom line is that we want to continue taking part in European research,” Riordan says. “We are exploring lots of back-up options to maintain our collaborations with European universities, through things like joint contracts and honorary professorships.”

However, Gosden points out that life split between two countries may not appeal to many. “To be eligible to apply for funding you have to spend considerable time in the other country. I wouldn’t have wanted to go abroad for three months at a time when I had young kids.”

Archaeology is not the only discipline feeling exposed. Analysis by the Royal Society [pdf] shows that arts, humanities and social science subjects are especially dependent on European funding. Europe also provides nearly a third of UK research funding in IT and just less than a quarter in chemistry.

Lee Cronin, regius professor of chemistry and one of the research stars at Glasgow University, says Brexit is driving him “insane”, because it is impossible to plan future research.

If Brexit ruins research, he won’t stay. “Although I’m British, if I can’t run a world-leading team of researchers here I’m not going to let the skills, knowledge and momentum we’ve built die because of a hard Brexit. Many of us will be forced to move our research abroad or seek joint affiliations in the EU.”

Cronin is frustrated that discussions about the potential impact of Brexit on science are being “drowned out” by other concerns. “The simple fact is that without alignment, UK science crashes out of the biggest collaborative network ever built in the history of humanity,” he says.

He has a team of 57 researchers: 20 are Europeans and 19 are from the rest of the world. He is furious about Theresa May’s recent pledge to reduce migration by giving priority to migrants, including those from the EU, earning more than £50,000. “Many of the researchers in our team earn less than £50,000, but skills-wise they are worth their weight in gold. So I’ve got a politically mandated brain drain since we would not be allowed to hire people below this level,” he says.

Johannes Angermuller, professor of discourse at Warwick University, says remaining part of the European research programme is about wanting to collaborate with the best people, as much as it is about money. “The prospect of being confined to an island is not appealing to any researcher,” he says.

But the head of one university, who wishes to remain anonymous, is cautiously optimistic. “Everyone you speak to in Europe admits that to have an EU research space without the UK would be a lose-lose scenario. They say if we ally with countries like Israel for research, why wouldn’t we ally with Britain?”

The vice-chancellor says that with a soft Brexit deal Britain should easily negotiate an “associated country” status on the next European research round. “But a cataclysmic no deal would, of course, put all of that at risk.”