British Prime Minister Theresa May will on Friday set out Britain's much-anticipated negotiating demands for its post-Brexit relationship with the European Union following a week of spats with Brussels.
Here's an outline of what we know so far about the country's departure from the European Union:
Britain will leave the EU on March 29, 2019, almost three years after the referendum vote for Brexit, having triggered the two-year Article 50 withdrawal process in 2017.
This date is defined in EU law and can only be extended through agreement by all 28 member states.
An interim deal was struck in December on the priority issues of the separation – Britain's financial settlement, the Irish border and citizens' rights.
EU chief negotiator Michel Barnier on Wednesday launched a 120-page draft document translating the December agreement into a legally binding text.
Britain has agreed to pay into the EU budget until the end of 2020 and meet its share of commitments made in the past but not yet paid out, putting the total cost at between £35 billion and £39 billion (39-44 billion euros, $48-54 billion).
The deal also states that EU citizens living in Britain and British citizens living in the EU before exit day would be able to claim permanent residency status for themselves and their families.
On Ireland, London has committed to avoid a "hard border" with checkpoints between British-ruled Northern Ireland and EU-member Ireland, which all sides agree is vital to maintaining the 1998 Good Friday peace accords.
It pledged in December to do this "through the overall EU-UK relationship" but if that cannot be achieved, Britain vowed to keep "full alignment" with the EU single market and customs union.
However, Prime Minister Theresa May this week rejected the EU's draft divorce treaty detailing the "backstop" solution in which Northern Ireland could stay in a customs union with the EU post-Brexit.
She said Britain would never allow the EU to "undermine" its constitutional integrity, and all eyes will be on her Friday speech when she unveils her own plans to avoid both this and a hard border on the island.
Britain and the EU have agreed there should be a transition period to keep relations on current terms and ease the withdrawal.
Brussels insists it should finish in December, 2020 – the end of the current EU budget cycle – and cannot be open-ended.
During this period Britain would keep paying into the EU budget as planned, trade on the same terms and accept European rules and regulations, but will have no say in those rules as it will not be a formal member.
Barnier has warned there were "substantial" disagreements between the two sides that meant an agreement was "not a given."
He cited rows over the future rights of EU citizens who arrive in Britain during the transition, and the bloc's demand that it be allowed to put up trade barriers if London reneges on the deal.
May has said Britain will leave the EU's single market and customs union after Brexit but wants a "deep and special partnership" in which trade continues with as little friction as possible.
She has rejected existing models of trading relationships, as they would require Britain to maintain free movement of workers, EU judicial oversight or give up its right to strike trade deals with other countries.
The prime minister says she wants a "bespoke" deal, but the EU has warned that Britain cannot cherry-pick what it wants.
Senior British ministers met last week in their first serious attempt to decide the details of their negotiation position, before talks on trade are expected to begin with the bloc in April.