The British home secretary has warned of Irish Border controls in the event of Brexit during a visit to Northern Ireland to campaign for a remain vote in Thursday’s referendum on the UK’s EU membership.

While in Co Down on Tuesday, Theresa May said it was “inconceivable” that there would not be changes to current arrangements between the North and the Republic if the UK votes to leave the EU.

The senior British cabinet member called to Denroy Plastics in Bangor, where she was accompanied by independent unionist MP Lady Sylvia Hermon, and also to Mash Direct in Comber, where she was accompanied by UUP leader Mike Nesbitt.

Ms May said that, while the Common Travel Area between the two countries existed prior to the EU, if there was a Brexit some form of control would be inevitable.

“It is inconceivable that a vote for Brexit would not have a negative impact on the North/South Border, bringing cost and disruption to trade and to people’s lives,” she said.

“Put simply, Northern Ireland outside the EU could not prevent free movement and continue with an open North/South Border.”

Economic argument

Ms May also claimed the “economic argument for Northern Ireland to vote remain is compelling.

“Not only does Northern Ireland rely on EU exports to a greater extent than nearly every other region of the UK, 50,000 jobs here are linked to EU trade,” she said.

“The local agrifoods sector is a major economic player and importantly Northern Ireland is a net beneficiary of European funding.

“In so many ways, the economic argument for remain is particularly strong in Northern Ireland.”

Tom Kelly, the Stronger In chairman in the North, said the Remain campaign is concentrating on getting people out to vote on Thursday.

“I am very confident that we well win both the argument in the UK and Northern Ireland,” he said.