Britain and the European Union on Monday enter a pivotal week that determines if they are still on course to reach amicable divorce terms -- and when Brexit might finally occur.
Queen Elizabeth II is due to step into the fray by performing her ceremonial duty of informing parliament about the government's agenda for the coming year.
But the odds of Prime Minister Boris Johnson's tenure lasting that long will depend largely on the outcome of hurried discussions held behind closed doors in Brussels around the same time.
EU leaders will then meet on Thursday and Friday for a summit held under the pressures of the October 31 Brexit deadline just two weeks away.
Diplomats see little hope that the sides can achieve in a few days what they had failed to in the more than three years since Britons first voted to leave the bloc after nearly 50 years.
"A lot of work remains to be done," EU negotiator Michel Barnier told ambassador Sunday.
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Technical talks are continuing -- variously described as "intense" or "constructive" -- but few familiar with the process can point to progress on the decisive issue of British Northern Ireland's place in the EU customs zone.
Johnson warned his ministers Sunday to brace for a cliff-hanger finish.
The British leader said "a pathway to a deal could be seen but that there is still a significant amount of work to get there and we must remain prepared to leave on October 31."