Lord Robert Winston warns of Brexit 'disaster' for universities
One of Britain's best known scientists said it could be a "disaster" for university research if Britain left the European Union.
Prof Lord Robert Winston said: "It's very clear if we came out of Europe, where we get much more out than we put in in science, we will lose massively."
The Labour life peer was speaking at the BioWales conference in Cardiff.
But the Scientists For Britain group is arguing that Britain would be no worse off by leaving the EU.
The group, which claims to have 150 members, said there were 13 countries outside the EU which successfully apply for European funding.
Lord Winston, a Labour life peer, said he was not speaking politically "but simply looking at it financially".
The professor at Imperial College in London said the figures were "incontrovertible" while collaborations, such as in engineering, could be lost.
"How you'd deal with European students who might not want to come here or be charged very different fees in future is a real problem for us," he told BBC Wales.
"We could see ourselves losing a lot of income which props up our university system right across the system."
Lord Winston, an In Vitro Fertilisation (IVF) pioneer and broadcaster, was speaking on changing genes at the two-day conference.
It brings together life science companies and academics from around the world.
Meanwhile, stem cell regenerative therapy company ReNeuron has opened its new headquarters in Pencoed near Bridgend, after moving from Guildford in Surrey. The company aims to create a further 70 new jobs over time.