Changes to UK immigration law would rob the country of some of its most valuable talent, according to a group of 15 leading economists.

In a letter to the Financial Times on Monday, the group - which includes professors from the London School of Economics (LSE), Cambridge and Oxford, as well as Nobel laureate Christopher Pissarides and Willem Buiter, chief economist at Citigroup and former member of the Bank of England's Monetary Policy Committee - said that proposals to means-test migrants risk damaging Britain's competitiveness.

The Home Office intends to cut the number of non-EU economic migrants to the UK by introducing a cap on those earning under a threshold salary, likely to be above £31,000 per year. Those below that level will have to leave after five years.

"Had such a policy been in place when some of the signatories to this letter were considering coming to the UK, they might have chosen not to come at all, or would not have been allowed to remain," the letter said. "We believe that this would be deeply damaging to the competitiveness of the UK science and research sectors, and to the wider economy."

The independent commission on migration has advised that the policy would lower the number of non-EU migrants and their families by two-thirds within five years, but the cost would be a reduction in growth in the UK equivalent to 0.29% of its gross domestic product (GDP).

Signatories also include Bangladeshi-born Sir Partha Dasgupta, emeritus professor of economics at Cambridge, one of the world's leading authorities on development and the environment; Princeton and LSE professor Nobuhiro Kiyotaki from Japan; and David Vines, Oxford professor and expert on global governance and institutions.

The government has long made the argument that talent is fungible, and that the best people will move to the location that offers them the most. However, that has tended to be made only in relation to discussions on higher rate tax and the financial sector.

The coalition has a stated aim of diversifying the economy away from financial services and towards high technology sectors, but quasi-academic jobs in scientific research, in particular, tend to be relatively low paid.

"The policy could almost have been designed to deter the migrants the UK most needs; and, for those who do come, to expel many of those we would most like to remain," the letter said.

"One cannot identify the next generation of entrepreneurs or Nobel laureates only a few years into their careers, and certainly not just by looking at how much they are paid," the letter said.