Britain says there is a 66 per cent chance of a Brexit trade deal but has sought to use Prime Minister Boris Johnson's deadline of October 15 to hurry the bloc's negotiators towards an agreement.
The two sides say they are inching towards a deal that would govern around $US900 billion ($A1.3 trillion) in trade after December 31 - when the current transitional arrangements end - though sticking points remain on fishing, level playing field issues and governance.
"The landing zone and the nature of the agreement is pretty clear if not exactly pinned down yet," David Frost, the UK's chief Brexit negotiator, told parliament.
"A deal is eminently achievable and could be achieved but equally it is possible that we won't get there."
When Johnson's Brexit supremo, Michael Gove, was asked by a Conservative MP if the probability of a deal was still 66 per cent, Gove said: "I think that's about right."
Frost cautioned the EU that an October 15 deadline set by Johnson on September 7 remained a deadline.
The EU is due to asses progress on a deal at an October 15-16 summit.
He added that Britain's "door would never be closed" and that a huge amount of textual work would need to follow October 15 if an outline deal was struck.
"As we approach the 15th - and it is very close already - I will have to advise the prime minister on whether the conditions in his statement have been met or not, and we will have to consider the situation at that point," Frost said.