A leading unionist has accused the Home Secretary of "talking nonsense" after she claimed that Brexit could hurt businesses in Northern Ireland.
Independent cross-bencher Lord Kilclooney also predicted that the Irish Republic would quickly follow the UK out of the European Union if people backed a Brexit.
"If the UK leaves the EU, there will be no strengthening of the border here because the Irish Republic will swiftly follow suit," the former MP said.
"The UK will have two years to negotiate the terms of its exit and, during that period, the Republic will leave too.
"As the main trading partner of the UK, it would be disastrous for them to remain."
Lord Kilclooney said that the farming community in the Republic would lobby strongly for an end to EU membership.
"Most of their beef, lamb and dairy exports go to the UK," he added. "They would be destroyed if we leave the EU, so they will do the same in order to continue trading with us."
Former Ulster Unionist MEP, Lord Kilclooney, also said Mrs May was "talking nonsense" after she predicted extensive border controls in the event of a Brexit.
"The very idea that we would have the equivalent of a Donald Trump-type wall around us is utterly ridiculous and, as someone who lives within 10 miles of the Border, I'd be very opposed to that," he explained.
During a visit here to support the Remain campaign, Home Secretary Theresa May said that it would be "inconceivable" that border arrangements with the Republic would remain the same if Britain decided to leave the EU.
After meeting staff at the Denroy Plastics manufacturing plant in Bangor, she said: "If you just think about it, if we're out of the European Union with tariffs on exporting goods into the EU, there would have to be something to recognise that between the Northern Ireland and the Republic of Ireland.
"If you pulled out of the EU and came out of free movement, then how could you have a situation where there was an open border with a country that was in the EU and had access to free movement?"
The Denroy group is one of Northern Ireland's most successful exporters, with annual sales of more than £10m.
Its range includes the popular hairbrush brand Denman, medical devices and aircraft components.
Denroy's finance director Kevin McNamee said: "From the group's point of view, we have a number of issues. One is that we're an exporter - about 40% of what we manufacture goes around the world.
"We're quite concerned about the impact of trade tariffs after a Brexit. Obviously, if we're exporting to anywhere in Europe, then a trade tariff could affect our competitiveness in that market."
The United Kingdom has voted to leave the European Union - sending shockwaves and uncertainty throughout the financial and political worlds leaving the Remain campaign in a state of incredulity and Prime Minister David Cameron resigning.