A leading Northern Ireland manufacturer says it has concerns about the impact on its export business in the event of a Brexit.
Kevin McNamee, finance director with the Bangor-based Denroy Group, said the company was worried about the prospect of new international trade agreements and punitive tariffs.
Denroy's products range from the world's best-known hairbrush brand, Denman, through medical devices and components for aircraft, including the Eurofighter Typhoon.
"We export to 80 countries and we're concerned about what's going to happen with trade agreements," Mr McNamee said. "A Brexit could mean jeopardy for these trade deals, the implementation of tariffs and other obstacles to trade. A lot of our business is in the EU and we're asking how that will work out. This uncertainty is a major issue for many companies in Northern Ireland.
"A major part of our business, with haircare, is retail and there's a concern that consumer spending will be affected if Britain leaves the EU."
Denroy is one of the Northern Ireland's most successful exporters, with annual sales of more than £10m, and is an important player in the local aerospace sector. It designs and manufactures lightweight plastic components used in structural wing and air frame assemblies, cabin interiors and cockpits of civil and military aircraft. Airbus is a major customer and the company makes at least 180 parts for the Eurofighter Typhoon, regarded as the world's most advanced combat aircraft.
Mr McNamee said: "One third of our business is in the aerospace sector and that's a very fragmented international industry, in that structures may be manufactured in Europe, shipped elsewhere in the world for further work, then assembled back in Europe, at Bombardier for example. What would renegotiated trade deals mean for that sector and our part in the supply chain?
"The uncertainty around these questions is a major problem for industry and there's very little understanding of the implications of leaving the EU, and little guidance on the subject."
He added that Denroy, like other manufacturers, would be hesitant about making investment decisions until after the EU referendum in June.
Mr McNamee was one of more than 120 businesspeople attending a CBI economic briefing in Belfast yesterday. Among the speakers was Professor David Phinnemore from Queen's University, who said the EU debate was "underdeveloped" in Northern Ireland.
"There's a huge amount of uncertainty ahead of us," he said. "If the 'leave' side wins, the new relationship with Europe is tricky because there's no real agreement between the leave campaigners about what that relationship should be, either a free trade agreement or an association agreement, which is far more tortuous to negotiate."
Fergal O'Brien, head of policy and chief economist at the Republic's main business organisation, Ibec, said the prospect of the UK leaving the EU was the "number one issue at the moment" for Irish companies.
"It's incredibly important because we would like to see a strong, reformed EU for all member countries and we think there are a lot more risks than opportunities facing us if Britain leaves."