There are hopes that a Brexit trade deal can be struck by Christmas, although EU chief negotiator Michel Barnier has suggested talks could go beyond January 1.
The next 48 hours are seen as crucial if a deal is to be reached and ratified by the end of the year in a bid to avert hugely damaging economic consequences for both sides.
The Government here still believes an agreement can be reached before Christmas with a source saying: “That’s the window to get this done.”
There are concerns that if the talks go into next week and down to the wire as the end of the Brexit transition period looms on December 31 that there could be “real problems”.