It says the problem is due to a lack of detail on how the Government would continue to support farming and food in the event of an exit.
The NSA says that while the inability to give long-term commitments is perhaps understandable, the Government should give firm indications of how farming and food production would be treated if the country was to vote to leave.
Phil Stocker, NSA chief executive, said: “Many people directly involved in agriculture are supportive of remaining in the EU, but increasingly I am talking to sheep farmers who are somewhat attracted to leaving, remembering that the UK joined a common market and not a ‘super state’.
“However, the politicians running the ‘out’ campaign can only give a personal opinion of what they might like to see in terms of investment and support for farming and food, not solid commitments.
“The farming industry needs firm assurances to base its decision on, not just opinion and ideas.
“Defra is currently working on its 25 Year Food and Farming Plan, which NSA believes should include a commitment to support and nurture agriculture in order to deliver that plan, with reference to a future in and out of the EU. We would like to see clear and committed plans and intentions for both options.
“Evidence over the last decade or more suggests the Treasury would reduce funding for agriculture.”