A report published by The Royal Society in December 2015 found that while the U.K. overall was a net contributor to the EU budget, it received more EU research funding than it had paid for.
"The U.K.'s contribution to EU research and development of 5.4 billion euros ($5.95 billion) over the period 2007–2013," the report said. "During this time, the U.K. received 8.8 billion euros in direct EU funding for research, development and innovation activities."
According to the open letter, 15 percent of academic staff at U.K. universities are from other EU states. In addition, the BBC reported that some U.K. firms had stopped receiving EU funds and U.K. academics were being left out of EU research projects.
Meanwhile, the National Farmer's Union (NFU) has warned that immigration restrictions as a result of a Brexit would affect the supply of seasonal labour.
"We need to be prepared to explore all the possible options in maintaining access to horticulture's vital labour supply," said Ali Capper, the NFU's horticulture board chairman, in a press release.
"What is also clear is that we are not just talking about access to seasonal labour - some sectors and businesses are currently reliant on non-UK workers in full-time roles, year-round."
In a letter to David Davis, the U.K.'s minister for Brexit, Mrs Capper said "non-U.K. workers are vital" to agriculture industry.
U.K. farming is highly reliant on migrant labour. A report by the NFU published in January found that agriculture employers had struggled to recruit a domestic workforce due to the seasonal nature of farming and had to hire from abroad: in 2014, there were 34,513 non UK-born workers employed in agriculture, according to the report.
"Any restrictions on our ability to recruit non UK-born workers would negatively impact the sector," the report warned.
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