Government cuts to science funding could lead to a brain-drain of talent from Britain, the chairman of the Lords science and technology committee warned.
Lord Krebs said there are already signs that researchers are going overseas or choosing not to come to the UK, even before the planned cuts have been imposed.
Business Secretary Vince Cable has said the Government will cut its research budget and strip out mediocrity, with only top-flight work attracting funding.
Lord Krebs told BBC Radio 4's Today programme that six leading universities were warning of an exodus of talent and he agreed with them.
"What they said was that the global market for scientific talent is highly mobile and people go where the resources are.
"There are already warning signs that, even with talk of cuts, leading talent is haemorrhaging, going overseas, or we are failing to attract that talent.
"This is not special pleading by the scientific community. The future of the science base is also about the future of jobs and the economy.
"We rely on our ability to attract talent from all over the world. That talent can equally well go elsewhere and there are already warning signs that it will."