BRUSSELS (Reuters) - Northern Ireland will not stay in the European Union's single market or the customs union after Brexit, a British government official said, adding that arrangements for the border with Ireland must not eat into the United Kingdom's integrity.
Allowing Northern Ireland to retain some access has been floated by the European Parliament's Brexit pointman, Guy Verhofstadt.
"We will leave the European Union in 2019 as one United Kingdom," the British minister for Northern Ireland, James Brokenshire, said on Monday. "We need to ensure that nothing is done that undermines the integrity of the UK single market."
"I find it difficult to image how Northern Ireland could somehow remain in while the rest of the country leaves. I find it impossible," he told a seminar in Brussels.
Brokenshire reiterated Prime Minister Theresa May's insistence that the United Kingdom would be exiting both as a result of the 2016 referendum.
London has proposed an "invisible border" without border posts or immigration checks between EU member Ireland and Northern Ireland after Brexit. But it has given no firm ideas on customs arrangements and the EU side has been mostly critical, saying these plans are unrealistic.
Dublin has said it will not let Brexit negotiations move from the divorce talks to discussions about future trade relations between Britain and the EU - as London is pushing for - without more guarantees on the border.
Irish Foreign Minister Simon Coveney has demanded more guarantees that the Irish issue would be solved even if the future trade talks between Britain and the remaining 27 EU states collapse.
Brokenshire said some agricultural laws in Northern Ireland -- which is trying to reach agreement on how to relaunch its regional executive that is ruled at arm's length from London -- were already different than elsewhere in the United Kingdom.
He signaled Belfast could keep some of its laws closer to those of the EU after Brexit to minimize trade disruptions across the future border.
He also said London was keen to preserve the single electricity market on the island of Ireland and hoped for close cooperation with Dublin, including on security matters, after Britain leaves, as is now due to happen in March, 2019.
British and EU negotiators will meet in Brussels again this Thursday and Friday for more Brexit talks that have been grinding slowly, unnerving investors and businesses who demand clarity to plan their future operations.
(Reporting by Gabriela Baczynska; Editing by Alison Williams)