As top scientists warn the Coalition against an immigration cap, Nobel Prize winner Professor Sir Martin Evans of Cardiff University writes that the "draconian" policy puts Britain's future at risk.

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Professor Sir Martin Evans FRS, President of Cardiff University, writes for Channel 4 News.

The Government, responding to a perceived problem and public pressure, has announced a draconian limit to immigration quotas.

It has asked the Home Office to achieve a decrease in net migration while continuing to attract the brightest and the best people who can help economic growth to the UK.

What must be realised is that one of the most important segments of "brightest and best" are the scientists and engineers of a very high calibre whom we welcome from abroad. These individuals typically do us a great service and should either be exempted from a cap on immigration or facilitated by a much more sensitive application of a points and priority system.

Careful studies (for instance "The Scientific Century: securing our future prosperity" a report by the Royal Society) have shown that research, and science and technology are powerful drivers for economic growth. Any limit on the immigration of non-EU scientists, technologists, engineers, and mathematicians will damage economic growth while having little impact on net migration.

Professor Sir Martin Evans

Financial entrepreneurs, investors, and elite sports people, are set to be excluded from the cap.

Skilled scientists and engineers are intellectual investors and entrepreneurs – investing their knowledge and skills creatively to advance the UK. They have a vital role to play in future economic growth.

It appears that the suggested immigration policy has been insufficiently thought through and the UK may lose out badly by damaging our science and technology at the research and development stage and also by denying industry vital skills.

Finally, it is worth pointing out that the US benefits hugely from skilled immigration and that over half of the vibrant start-up companies in California’s Silicon Valley depended upon the initiative of immigrants.

In the UK we look to these individuals not just to fill skills' shortages, but to use their internationalism to bring different perspectives and networks to support our economic growth.