One of Britain's most distinguished scientists, Prof Sir Paul Nurse, says the government is "shooting itself in the foot" with its visa system for science researchers.
Sir Paul told BBC News that high visa fees are deterring early-career researchers, who are instead being welcomed by the UK's economic rivals.
Supporters of the current system say higher visa costs help to fund the NHS and reflect wider public concerns about immigration.
But the Nobel prize winning scientist says the UK's scientific future is being put at risk.
"Having expensive visa costs is shooting yourself in the foot. It absolutely doesn't help in attracting these sorts of people," Sir Paul said.
