Britain will complete its departure from the EU on Dec. 31 when its current free trade arrangements expire. The two sides have been struggling for months to define a new relationship covering everything from trade to transport and energy.

The much-delayed final stages of the already tortuous negotiations now coincide with a fresh crisis after EU members and other countries suspended most travel to and from Britain to curb a new, more contagious variant of the coronavirus.

“We are really in a crucial moment. We are giving it a final push,” said the negotiator, Michel Barnier, as he arrived to update the bloc’s 27 national envoys on Brexit.

Irish Prime Minister Micheál Martin said he believed negotiators were more likely than not to strike a deal, but that talks may go beyond Dec. 25.