Plans to limit the numbers of international students coming to the UK have been labelled "nonsensical and counterproductive" by leading academics.
It comes as three former university ministers have voiced their concerns, calling it a "catastrophic mistake".
Last week, Prime Minister Rishi Sunak announced potential plans to clamp down on international students taking “low-quality” degrees in a bid to bring down net migration.
It has led to claims the move could make some universities bankrupt.
Professor Ian Walmsley, Provost of Imperial College London, said international students are "irreplaceable".
"The UK government estimates we need at least an additional 150,000 researchers and technicians by 2030 to reach our science goals," he told The National.
"We have no chance of achieving this unless we can support the education of UK STEM students and attract the best and brightest international students.
"Our international students make an irreplaceable contribution to the UK economy – worth around £29 billion a year - which we cannot afford to lose.
"International students are also entrepreneurial and start companies here that create jobs, fuel innovation and benefit society.
"We must signal, now more than ever, that the UK is open to international talent. It is in the interests of everyone in the UK to do so."
Vice-chancellor at the University of Hull, Professor Dave Petley, said the move would be "foolhardy".
"It is very disappointing to see this nonsensical and counterproductive attack on international students this morning," he said.
"They are a force for good for home students, for our communities, for our economy and for international relations. Banning them would be startlingly foolihardy."
On Sunday, former education minister Jo Johnson said the move would be a "catastrophic mistake".
“Other countries look with envy at the UK’s appeal to global talent,” he told The Observer.
“Higher education is one of our few globally competitive sectors and strong demand reflects its high standing in countries that are central to our post-Brexit positioning, including India. Finally, it’s hard to imagine a policy more likely to harm UK ambitions to become a science superpower and to level up across the country than a mindless crackdown on international students.”
Fears have been raised that the move could see overseas students opting for European universities instead, in countries like Germany, which do not charge fees.
It comes as the Germany Embassy recently revealed the nation was offering more than 1,800 courses in English.
The prime minister is considering a crackdown on international students bringing dependants and restricting admissions to top universities, Downing Street said on Thursday after net migration to the UK climbed to a record half a million.
His official spokesman insisted Mr Sunak is “fully committed” to bringing overall immigration levels down and blamed “unprecedented and unique circumstances” for the record high.
“We’re considering all options to make sure the immigration system is delivering, and that does include looking at the issue of student dependants and low-quality degrees," his official said.
This would be in line with proposals being explored by Home Secretary Suella Braverman, who has previously complained about foreign students “bringing in family members who can piggyback on to their student visa” and “propping up, frankly, substandard courses in inadequate institutions”.
The Northern Powerhouse Partnership has raised concerns the move could bankrupt universities in deprived areas, like Hull, where attracting "international revenue and talent" was vital to their survival.
Chairman of the government’s Migration Advisory Committee, Professor Brian Bell, believes the move could “send many universities over the edge”, particularly in poorer regions.
“Most universities for most courses lose money on teaching British students and offset that loss by charging more for international students," he told BBC Radio 4’s Today programme.
“If you close down the international route I’m not sure how the university continues to survive.
"What about Newcastle, what about the North East, the North West, Scotland?
“If you’re interested in the levelling-up agenda, you might want to worry about harming universities around Britain."
He pointed out that it is not just an immigration policy but also an education policy, as it could lead to a “massive increase” in British students’ fees to make up for the loss of foreign students’ payments.
The number of dependants joining Master's and PhD students has risen from 20,000 to 80,000, Prof Bell said.
Around 504,000 more people are estimated to have moved to the UK than left in the 12 months to June 2022, up sharply from 173,000 in the year to June 2021.
The estimates were compiled by the Office for National Statistics, which said the jump was driven by “unique” factors, including visa schemes for Ukrainians and Hong Kong citizens, and students arriving from outside the EU.
People arriving on study visas accounted for the largest proportion of long-term immigration of non-EU nationals, at 277,000, or 39 per cent of the total, according to the ONS.
