The UK is “open to global talent”, the government declared last week, with a new visa designed to woo the best overseas researchers. But angry academics say their protests about the Home Office’s “shocking” refusal to grant residency to Dr Asiya Islam, an “unequivocally superb” Indian sociologist at Cambridge University, have fallen on deaf ears.

Senior academics warn that unless the government reins in its aggressive application of immigration rules, talented international researchers will not want to come to the UK.

Dr Islam, 31, an expert on gender and class in urban India, has lived in the UK for a decade but the Home Office refused her application for indefinite leave to remain in November, saying she had spent too many days out of Britain during the application period. She had spent a year in Delhi conducting field research for her PhD – which has been backed up by Cambridge University.

Prof Beverley Skeggs, distinguished professor in the sociology department at Lancaster University, says: “What hope is there for bright young global talent if they are treated like this? And if this is happening at Cambridge, one of our most elite universities, what on earth is happening elsewhere?”

She adds: “I think Asiya’s case has sent shockwaves across the academic community here and internationally, because no one realised things were quite this bad.”

The government’s global talent visa, announced for researchers, will allow universities, funders and learned societies, including the Royal Society, the Wellcome Trust and the British Academy, to endorse applicants.

Boris Johnson said: “As we leave the EU I want to send a message that the UK is open to the most talented minds in the world, and stand ready to support them to turn their ideas into reality.”

But many academics say that message is being drowned out by the hostile immigration environment. The Guardian has recently reported on a number of other cases, including three at Oxford and one, Furaha Asani, from Leicester University. Dr Asani is under threat of being deported to the Democratic Republic of Congo, a country she has never visited.

Dr Islam is widely regarded as an outstanding young academic. She was a Gates scholar at Cambridge, and was recently awarded the prestigious Joyce Lambert research fellowship at the university. Skeggs, who examined Islam’s PhD thesis, describes her as “a superb scholar – unequivocally superb”.

Earlier this month Islam delivered a letter of protest about her treatment to the Home Office, signed by 2,000 academics, including 183 professors. She is furious that her campaign for residency has been met by silence from both the Home Office and the universities minister, Chris Skidmore.

“I think I’ve had such an outpouring of support because mine isn’t an isolated case. It’s symptomatic of how migrant academics are being treated in the UK,” she says. “So many people have reached out to me and said they have been through exactly the same.”

Islam lodged an immediate appeal against her Home Office refusal in November. However, Cambridge advised her to protect herself (her visa ran out last week and, as an “over-stayer”, she would not have been able to work or rent a home), by applying for a temporary tier 2 visa for the three years of her fellowship. While this has been granted, to apply, Islam has had to drop her residency appeal.

“I now have no right to challenge what has happened. It didn’t really feel like a choice. How am I supposed to carry on if I am homeless and jobless?” she says. “My new visa will run out in less than three years and then I won’t be entitled to apply for the permanent right to remain.”

Prof Sarah Franklin, head of sociology at Cambridge, fears Islam’s case sets “a very worrying precedent”. “She wasn’t in the UK because she had compelling reasons not to be: she was conducting her academic research,” she says. “We are operating in a very febrile, irrational, volatile context, in which the normal rules don’t seem to apply.”

Skeggs agrees. “What is happening to Asiya is absolutely shocking. It is parochial provincialism that completely contradicts everything the government claims to believe in when they say they are supporting global talent.”

The Home Office said it was unable to comment on individual cases.

Dan Engström, a professor in building construction at Luleå University of Technology, Sweden, says that many international academics are watching the treatment of academics like Islam with horror.

“We are flabbergasted by the way the climate of debate in the UK has deteriorated, how the hostile environment is affecting people who have made Britain their home for decades,” he says.

He and his wife had been considering a move to the UK in the future, but the harsh immigration environment had “completely put me off”. He adds: “The silent acceptance of xenophobia and the hostile environment policies would have to go first.”

But Martin Smith, policy manager at the Wellcome Trust, says that allowing learned charities like his to endorse the new talent visas will be “game-changing”.

“There is also real recognition that science is done by teams and if you are doing a named role, on a grant your application will be prioritised too”, he says.

Wellcome is now lobbying the Home Office to reduce visa costs for academics, which outstrip other countries.

Smith is also asking UK academics to pass on any recent evidence of visiting academics having visas unfairly refused for conferences or research meetings.

The charity has collated more than 100 cases where international scientists have had their visitor’s visa application declined without a reasonable explanation. These are disproportionately from low-income countries, especially in Africa.