A new EU-UK trade agreement will "definitely" not come together on Sunday night, an official with the bloc said, adding that three most contentious issues remained unresolved.

Some reports on Sunday afternoon said agreeing fishing quotas and access for EU vessels to UK waters from 2021 was almost done but the official said that was not the case.

The person, who spoke under condition of anonymity, added that ways to settle future trade disputes and guarantee economic fair play for companies were also not yet settled.

The head of the EU's executive, European Commission President Ursula von der Leyen, and British Prime Minister Boris Johnson are due to talk again on the phone on Monday afternoon to try get above the line a new partnership pact.