FREE movement will be "absolutely essential" if Scotland is to retain its status at the cutting edge of life science research in Europe, according to industry experts who warn that the sector is already facing up to a potential brain drain as top talent heads abroad.

Professor Andrew Morris, Scotland's chief scientist for health and a key advisor to the Scottish Government, writes today in The Herald that he wants Scotland to be "recognised globally as the natural home of health science", but over the past decade only seven per cent of European research cash has gone to non-member states such as Norway and Switzerland.

Both countries have negotiated an "associate membership" which enables them to access EU research funding, but only on the condition that they accept free movement and pay into the funding pot in line with their GDP - while at the same time forfeiting the ability to influence the EU's science and research policies.

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Professor Neva Haites, vice-president of life sciences for the Royal Society of Edinburgh and professor of medical genetics at Aberdeen University, said: "[Free movement] is absolutely essential. "It's not just a cornerstone of funding, it's a cornerstone of having the best possible scientists working in Scotland and collaborating. It's been unbelievably useful."

Switzerland has already discovered the consequences of trying to close its borders. Its full association with the Horizon 2020 programme - an €80 billion (£69bn) EU Research and Innovation scheme running from 2014 to 2020 - has been suspended since it voted in 2014 to place restrictions on from EU member states. From 2017, it will either need to scrap restrictions on freedom of movement for EU citizens or accept "third country" status, meaning that Switzerland could join European collaborative research projects but would not be entitled to any direct funding from the EU.

The UK is currently a net beneficiary of the programme, second only to Germany, and Scottish organisations alone have so far been granted €250 million (£217m) - much of it invested in health-related research.

Scotland is home to the UK's second largest life sciences cluster, one of the largest in Europe, with an annual turnover of more than £3.2bn. Scottish scientists lead the way in areas including drug discovery, stem cell research, and immunological studies into debilitating conditions such as multiple sclerosis. At the Beatson Institute in Glasgow, Scotland's leading cancer research body, half the researchers are non-UK EU nationals.

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However, there are already signs that Brexit uncertainty is undermining the sector.

Prof Haites said: "Ever since the vote occurred it's become more difficult to persuade people to come and work in the UK, and Scotland. It's meant that many people who are European have found other opportunities and left the UK, because they are not certain what their status will be.

"And when it comes to applying for 2020, there are examples of people who were going to lead on an application who have been told 'look, we don't really want the UK leading because we don't know what effect it'll have on the chance to get funding'."

Prof Morris added: "Scientists in Scotland are concerned about the position post-Brexit and its impact on our ability to compete and remain amongst the leaders in health research on the world stage. They question whether we’ll remain an attractive destination for talented researchers from elsewhere."

There are potential opportunities for a UK outside of the EU, however. Onerous red tape led to a 25 per cent decline in applications to conduct clinical trials in the EU between 2007 and 2011, prompting drug companies to pursue their studies in countries such as China and India instead. There is a possibility that leaving the EU could enable the UK to attract more clinical trials.

Research into GM crops has also been hampered by EU regulations which add €10-20m (£8.6-17.2m) to the cost of developing a new GM variety, driving companies elsewhere and leading the European Academies Science Advisory Council (EASAC) to warn that the EU is "falling behind new international competitors in agricultural innovation".

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EASAC also insists that there is "no rational basis for the current stringent regulatory process".

Although the Scottish Government has banned the growing of GM crops in Scotland, outside of the EU it could spearhead research into "genome editing" - an emerging field of plant research which enables scientists to make precise and advantageous mutations to a plant's genetic code without leaving any trace of foreign DNA.