Britain's Prime Minister Theresa May and Jean-Claude Juncker, President of the European Commission leave after making statements at the Commission in Brussels. Photo: Reuters / Yves Herman

After a breakthrough agreement on the UK’s exit settlement amount last week, and more optimism among negotiators this morning, Brexit talks failed Monday to reach consensus on divorce terms. The main sticking point was reportedly how to maintain an open Irish border.

“We had an agreement this morning,” Irish Prime Minister Leo Varadkar was quoted by the AP as saying, expressing disappointment.

“Despite our best efforts and the significant progress we and our teams have made over the past days on the remaining withdrawal issues, it was not possible to reach an agreement,” EU Commission President Jean-Claude Juncker was reported as saying. But he stressed, after a long lunch with UK Prime Minister Theresa May, “this is not a failure.”

Negotiators will have to reconcile differences between the British government’s position and Northern Ireland’s Democratic Unionist Party, which insists that there be no regulatory divergence which would separate Northern Ireland from the rest of the UK.

Time is running short to come to an agreement before next week’s EU summit, which will decide whether to broaden talks to other important issues such as trade. Failure to reach an agreement on initial settlement terms could significantly delay further negotiations.