"A UK source now says agreement on a UK/EU trade deal is again possible tomorrow", political editor Robert Peston said in a tweet just before midnight on Tuesday.

"Presumably because, says a separate source, there was movement late tonight on access to the 6-12 mile (offshore) zone, ocean fishing and the sanctions regime after the interim period of moving towards new quotas", he added.

The European Union is making a "final push" to strike a Brexit trade deal with Britain, although there are still deep rifts over fishing rights, Michel Barnier, the bloc's chief negotiator said on Tuesday.

Earlier on Tuesday, Peston tweeted there was no chance of a Brexit trade deal being agreed before Christmas, but one could still be reached in time for the British parliament to ratify it before Dec. 31.

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 UK wants to gradually curb EU access to its fishing waters over three years, while the bloc is proposing six years, to give its fishing industry longer to adjust.

The much-delayed final stages of the already tortuous negotiations have coincided 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 novel coronavirus.

(Reporting by William James and Aakriti Bhalla; Editing by Chris Reese and Kenneth Maxwell)