Talks between the UK and EU are due to resume in Brussels in a final bid to reach a post-Brexit trade deal.
Disputes over fishing and business competition rules are still going on, but the UK government said there was "still time to reach an agreement".
The EU mood was described as "downbeat" ahead of chief negotiator Michel Barnier meeting the UK's Lord Frost.
Prime Minister Boris Johnson will speak to European Commission President Ursula von der Leyen on Monday evening.
If no deal is done by the end of the year, the UK and EU will introduce tariffs and border checks on goods.
The BBC has learned that Mr Barnier briefed EU ambassadors early on Monday morning that "divergences" remain.
Cabinet Office Minister Michael Gove has arrived in Brussels for a meeting with European Commission Vice-President Maroš Šefčovič.
UK-EU negotiations resumed on Sunday, with disputes over fishing rights, competition rules and how to enforce agreed rules still causing problems.
EU sources suggested on Sunday evening that a breakthrough in talks on fishing was close to being made, but Downing Street denied this, with Irish Foreign Minister Simon Coveney later saying the claim had not been "borne out by the facts".
