James Brokenshire: Customs union would stop UK negotiating international trade deals

However, he told businesses across the island of Ireland that there would be a period of implementation where the UK would adhere closely to the existing customs union.

Speaking following a meeting with the Irish and British Chamber of Commerce in Dublin today Mr Brokenshire said businesses had voiced their "desire for certainty, not wanting to see cliff edges, sudden shifts."

"We think it is important there is an implementaion period where the UK would adhere closely to the existing customs union," said Mr Brokenshire.

"But ultimately it is about the UK being able to negotiate international trade deals. We want to harness those freedoms. If we were to remain in the customs union that would prevent us from doing so.

"We are leaving the EU, customs union and single market. We have set out options as to how we can achieve that frictionless trade," he added.

Mr Brokenshire said he had also reassured business leaders during the meeting of the UK's intent to ensure there will be no return to a hard border across the island of Ireland.

He has also scheduled meetings in Dublin with the Justice Minister Charlie Flanagan, Tánaiste Frances Fitzgerald and Foreign Affairs Minister Simon Coveney.

Minister Flanagan and the Secretary of State took the opportunity to discuss the ongoing security threat on the island of Ireland from paramilitary groups opposed to peace.

Mr Flanagan said: "Paramilitary groups opposed to peace remain the greatest security threat on the island of Ireland. The Gardaí and the PSNI continue to work together effectively to tackle these groups and their associated criminality.

"The Fresh Start Agreement has a particular emphasis on tackling paramilitarism and breaking the stranglehold of terrorists and thugs on vulnerable communities.

"As Minister for Justice and Equality I am fully committed to doing everything I can to counter these threats and protect our Peace Process."