The Brexit vote has already contributed to the departure of a Norwich-based scientist, with local research directors fearing more could follow.

Directors of two of the major institutes at the Norwich Research Park have spoken of their concerns that Britain's decision to leave the European Union is already having a negative impact on the country's science industry.

They urged the government to negotiate a deal which will allow the UK to retain access to EU scientists, programmes and funding.

But leading Vote Leave campaigner David Campbell Bannerman said Britain would be more global and less regional after it leaves the EU.

'We are in a period of uncertainty ... It is casting on research projects and it has had some effect. Once the government comes out with 'right, this is the model we want to achieve', then I think it is going to become clearer what happens to science and education.'

He believed a fee could be negotiated to allow access to the Horizon 2020 project, a major EU fund. He also claimed he had been told by a science commissioner that they would rather research projects were more international.

Professor Neil Hall, director at the Earlham Institute, a post doctoral molecular biologist, said the referendum result was a contributing factor in a decision by an academic to return to the Netherlands.

He said: 'I don't think there are European people who instantly think 'I am going to leave the country', but it can be a contributing factor...

'Partly because it leads to uncertainty in the economy. It makes you think about your job because there could be less investment in science because of the economic downturn, there is the uncertainty of what your status might be and whether you have to apply for a visa, and if your family might be able to work there and whether you would be able to apply to the EU for money. That is a major contributor to the science budget in this country,' he said.

He also warned that while there had not been any projects at his institute which had been put on hold, they may be less likely to apply to European funds because the uncertainty over Britain's status would make it seem a more risky strategy.

He said he knew of several incidents where UK scientists have been asked to leave EU consortia bids, although not at the Earlham Institute.

Dale Sanders, director of the John Innes Centre, said it had 'experienced resistance' from both academic and industrial European partners to JIC scientists participating in new proposals, due to be submitted in September.

'Article 50 has not been triggered, yet the vote has begun to have an impact on our ability to advance our research,' he added.

He added that leaving the European Union would make the John Innes Centre's mission of searching for scientific solutions to the global challenges of hunger and improving human health harder to deliver.

He said it was asking the UK government to be positive about UK science as an international endeavour, calling for ministers to negotiate the best deal for the UK to retain access to EU scientists, EU programmes and EU funding.

But Professor Ian Charles, director of the Institute of Food Research and founding director of the Quadram Institute, said it was too early to say what the implications were.

'It is important that the UK continues to play a leading role in European and international research and that there is recognition that EU and international students make an important contribution to the UK's world-class science base,' he added.

'Throughout the transition period the Institute of Food Research and shortly the new Quadram Institute will actively engage to secure support to enable our science to continue to be global in its outlook, internationally networked and an attractive destination for talented people from across Europe as well as elsewhere.'

He said it was particularly important for the Quadram Institute (QI), which is due to be completed in 2018.

'The QI will be at the forefront of a new era of food and health science as it aims to develop solutions to worldwide challenges in human health, food and disease. It brings together research teams from the Institute of Food Research, the University of East Anglia and the Norfolk and Norwich University Hospital.

'Collaboration is at the heart of what we are building on the NRP, capitalising on the unique resources co-located here. By its nature, QI's research is interdisciplinary and we are recruiting for a number of positions to bring talent from across the world to add to our teams.'

A spokesman for the Norfolk and Norwich University Hospital said; 'Our research programme is continuing as normal. It is too early to say what the potential impact might be.'

Is Brexit having a negative effect on your industry? Email annabelle.dickson@archant.co.uk