UK business and university leaders have written to the Chancellor warning him against cutting the graduate visa route due to the "serious impact" it would have on research and innovation.
More than three-quarters (77%) of research and innovation activity takes place in higher education institutions across the UK.
Chiefs from 17 Chambers of Commerce and business networks from across the country have signed the letter, as has the Russell Group and Universities UK.
It says any restrictions on the graduate visa route would "have a serious impact upon R&D capacity and return on government investment, besides causing damage to the wider economy",
The higher education sector in itself is the second largest investor in research in the UK, spending £5.6bn in 2021.
Most of this investment is generated by tuition fee income from international students, according to letter signatories.
Vivienne Stern, chief executive of Universities UK, said the country seems "intent on dismantling" the benefits of international students, and warned that any changes to the graduate route will mean a decline in the UK's research power.
She said: "Universities of all shapes and sizes will need to make difficult choices about where to invest diminishing resources.
"This will mean further cuts to staffing, courses and research investment.
"The business community and the higher education sector alike are worried about this because we know what it means: a crushing blow to our local economies."
James Harrington, chair of the University Alliance, added: "“The government would need to find ways of covering the significant losses to research funding and wider export income caused by declining international student numbers.
"This would be an extraordinary economic own goal."