Britain and the European Union are due to outline competing visions, on Monday, of the trade deal they will seek to negotiate, following Britain’s formal departure from the bloc.
On Friday, Britain ended its 47-year membership of the EU.
The two sides now have until the end of the year to agree on their future relationship.
A transitional phase until then means little changes in the practice.
EU Chief Negotiator, Michel Barnier, is due to present the European Commission’s draft negotiating mandate at 11 am (1000 GMT).
This must be approved by the bloc’s 27 governments and the European Parliament before talks with London can begin.
Brussels has stressed that British access to the EU market will depend on how fully it signs up to the bloc’s rules on issues ranging from the free movement of people to environmental and labour standards.
Britain, meanwhile, insists that it has not left the bloc to remain shackled by its rules.
“We want to have the best possible relationship with the United Kingdom.
“But it will never be as good as membership,’’ the Commission’s President, Ursula von der Leyen, said on Friday.
In a speech on Monday, British Prime Minister Boris Johnson is due to lay out his vision of a trade deal similar to the one Brussels struck with Canada while insisting that London will maintain high standards “without the compulsion of a treaty’’.
EU officials warn that the end-of-year timeline is extremely ambitious.
If this does not succeed, the trade will be based on an existing framework of minimal rules, Johnson is to say – akin to a no-deal scenario.