The party produced a list of 21 leading scientists who have left the country, but back the party's policies. However, Adam Ingram, Labour's science minister, was quickly forced to admit that he knew of no scientist who would definitely book a 2 May flight back if Labour wins. But he put this down to scientists' careful nature.
"They're people who always test something on the basis of the evidence available," he said. "They're predicting change, but will want to test it."
Figures suggest many expatriate British scientists will be watching for news from their homeland in the next 15 days. The Royal Society has found that the number of its members - typically top scientists - living abroad has risen to 24 per cent, compared with 17 per cent in 1970 and less than 20 per cent in 1980.
Separate figures from universities show that in 1994, 5.8 per cent of science and technology postgraduates left Britain after getting their higher degree, compared with only 1 per cent of other graduates.
Among the names put on show by Labour were Paul Davies, the top cosmologist who emigrated to Australia in 1990, "largely out of disillusionment with government policy"; Nobel prizewinner Sir Harold Kroto whose award-winning work was carried out in the US; Ron James of PPL, the company which jointly produced Dolly the cloned sheep; and Professor Michael Duff, now a Distinguished Professor at Texas A&M University.
Professor Davies said, "I am sure that should Labour have a chance to put their ideas into practice, we will certainly see some scientists coming home."
Mr Brown also emphasised that scientists and would-be inventors could benefit from the party's plan for an independent charity, the National Endowment for Science, Technology and the Arts (Nesta), to which they could donate patents and copyrights of their inventions and discoveries, so that future royalties could fund start-up projects.
But the Nesta proposal was criticised by John Mulvey, of the independent pressure group Save British Science, who said that it would require a change in research funding systems to work.
"It's a worthy idea, but a worrying development under the very mean funding regime is that universities and scientists are obliged to patent their work so that some money returns to the universities. That's almost the expectation under the present regime.
"I think that unless funding for 'blue skies' [undirected] research is more adequately available, then universities and individuals will find it harder to hand over their patents to a trust."Reuse content