Ministers from the EU have approved their mandate for post-Brexit trade talks with the UK.
The document – approved by the EU General Affairs Council on Tuesday – will be the basis for the negotiations, to be carried out by Michel Barnier.
It says that EU standards should serve as “a reference point” in any future trade deal.
Meanwhile, UK ministers will also meet at No 10 to discuss the government’s opening stance for negotiations.
The final agreement is due to be published online and presented in Parliament on Thursday.
The EU’s mandate – a 46-page document – says that its “envisaged agreement should uphold common high standards, and corresponding high standards over time with Union standards as a reference point”.
It says this should apply “in the areas of state aid, competition, state-owned enterprises, social and employment standards, environmental standards, climate change, relevant tax matters and other regulatory measures and practices in these areas”.
BBC Brussels correspondent Adam Fleming said: “This is the blueprint that [EU chief negotiator] Michel Barnier will follow in the negotiations.
“We’ve learnt from experience these documents are very important because the EU will only accept a final outcome that is pretty similar to this starting point.”
It is “the roadmap for all the rows we’re going to have over the next few months”, our correspondent added.
Nathalie Loiseau, an MEP for French President Emmanuel Macron’s La République En Marche! party, said the bloc wanted clarity about what the UK wanted to achieve in trade talks.
“If you would like to lower the standards [in areas such as food, farming], there would be mechanism to protect us from any sort of unfair competition,” she told BBC Radio 4’s Today programme.
“But the question I would like to ask is: what sort of discussion will your government have with other trade partners? Will you abide to American standards in terms of consumer protection for instance? This is still unclear to me.”
It is expected that ministers in the UK will commit to seeking a Canada-style agreement with zero tariffs, a proposal Mr Johnson and his Europe adviser David Frost have set out in speeches in recent weeks.
But the push for a Canada-style deal could set up a clash with the EU after its chief negotiator Mr Barnier ruled out such an agreement.
Mr Barnier has previously said the UK is too close in proximity to be permitted to compete with the other 27 member states on such terms.
And Ms Loiseau said that “to my knowledge the UK is not Canada”, adding that the EU-UK relationship is “very different” from the one with Canada.
‘Tough road ahead’
Arriving at the meeting of the General Affairs Council in Brussels, Croatia’s European Affairs minister Andreja Metelko-Zgombic said the EU would be willing to offer a “substantial” and “ambitious” partnership in trade talks.
But Dutch foreign minister Stef Blok warned it will be “very hard work” and a “tough road ahead”.
And Irish Deputy Prime Minister Simon Coveney said the prospect for a UK-EU free trade agreement will be “damaged significantly” if Britain did not build the infrastructure required for checks on goods crossing the Irish Sea.
The offer the EU was making to the UK was “generous and fair”, he said.
BBC assistant political editor Norman Smith said the EU’s proposals “have been given a decidedly cool response from government sources”, who say the UK’s priority is about control.
He said the “mood music” from Number 10 was that the prime minister “is quite prepared to walk away” and use World Trade Organization (WTO) rules.
When countries do not have free-trade agreements they use these terms. Under the WTO rules, each country sets tariffs – or taxes – on goods entering.
Mr Johnson will chair his EU Exit Strategy (XS) committee later, which includes new Chancellor Rishi Sunak, Foreign Secretary Dominic Raab, senior Cabinet minister Michael Gove and new Attorney General Suella Braverman. All supported the Vote Leave campaign in 2016.
The prime minister’s official spokesman, asked about the trade talks on Monday, said: “The UK’s primary objective in the negotiations is to ensure that we restore our economic and political independence on 1 January 2021.”
Mr Frost and his team will head to Brussels for the first round of negotiations on 2 March.
One clash expected between the UK and EU is on fishing, with leading member states speaking regularly about wanting continued access to UK waters.
In a speech in Greenwich, south-east London, earlier this month Mr Johnson announced that, once free of the EU’s Common Fisheries Policy, “British fishing grounds are first and foremost for British boats”.
But French Europe minister Amelie de Montchalin signalled fishing would be a flash point when the two negotiating teams come together in London and Brussels over the coming months.
“The fishermen have the right to be protected, they know very well that if we sign a bad deal they will lose enormously,” she told TV station France 2.
The document also says that the UK should return “unlawfully removed cultural objects to their countries of origin”.
The passage is thought to refer to the Elgin Marbles, ancient Greek sculptures taken to Britain more than 200 years ago and now on display in the British Museum.
Downing Street has insisted the future of the marbles is “not up for discussion as part of our trade negotiations”.
The prime minister is expected to meet Austrian Chancellor Sebastian Kurz in No 10 on Tuesday as part of his diplomatic efforts with EU leaders before talks commence.
The transition period runs until 31 December 2020, during which time the UK continues follow EU rules – including freedom of movement.
It is intended to allow time for the UK and the EU to agree a post-Brexit trade agreement.