In the event that an informal October deadline for a Brexit agreement is missed, diplomats in Brussels say an emergency summit will probably be held in November. Delays in reaching an agreement has sparked fears that Britain may simply stumble out of the European Union with no deal.

“I’m not going to say (it must come in) October. A few days here or there, beginning of November. But not much later than that, certainly,” Michel Barnier told a joint news conference with Britain’s Brexit minister, Dominic Raab, on August 21.

The October 18-19 summit of all EU leaders has long been cast as the make-or-break moment for a Brexit deal.

As reported by the Reuters news agency, both men agreed that, while there has been progress in drafting possible cooperation between the EU and Britain on security and defence after Brexit, the Irish border and trade ties were still the key sticking points.

“If we have that ambition, that pragmatism and that energy on both sides, I’m confident we can reach that agreement by October,” Raab told the same news conference.

But some Brussels diplomats told Reuters the process could even slip into December, leaving little time for ratification of an agreement before Britain becomes the first country ever to leave the EU in March 2019.

“There is definitely going to be a real push for October and we’ll probably not be able to quite get there. So, while it has not formally been confirmed as yet, an extra summit in November looks most likely,” said a senior EU diplomat.