The Brexit deal approved by MPs on Thursday addresses the most immediate separation issues arising from Britain's decision to end almost half a century of European Union membership.

The EU Withdrawal Agreement, which is being enshrined in UK law by the Withdrawal Agreement Bill, also includes plans for a transition period starting after Brexit day on January 31.

Here are the main points of the divorce deal:

The Brexit deal provides for a post-Brexit transition period until December 31, 2020, during which time things will stay pretty much the way they are now.

The intention is to provide continuity while both sides agree a new partnership, covering everything from trade to fishing rights and security.

When the divorce deal was first drafted, the transition was due to last almost two years. But Brexit delays have shortened this to just 11 months.

Flow chart showing what might happen next in the Brexit process.
Flow chart showing what might happen next in the Brexit process. AFP / Gillian HANDYSIDE

The EU has warned it will be impossible to agree a comprehensive free trade agreement within that time, and London has the option to extend the transition by a year or two.

But Prime Minister Boris Johnson insists there will be no extension, raising speculation that he will have to accept a less ambitious trade deal.

The loose outline of the kind of relationship both sides want is set out in a Political Declaration accompanying the EU Withdrawal Agreement.

The EU deal protects the rights to live, work, study and claim healthcare and social benefits of around 3.6 million EU citizens in Britain, and one million Britons living elsewhere in the bloc.

Britain's Withdrawal Agreement Bill also covers similar deals relating to citizens of Switzerland, Iceland, Liechtenstein and Norway, which are outside the EU but inside Europe's free trade area.

In Britain, European nationals arriving within the transition period must register before June 30, 2021, to retain their rights.

Residents of more than five years will be granted "settled status", or indefinite leave to remain, while more recent arrivals will be allowed to stay until they meet the threshold.

The Brexit deal provides for a post-Brexit transition period until December 31, 2020
The Brexit deal provides for a post-Brexit transition period until December 31, 2020 AFP / Kenzo TRIBOUILLARD

London says EU citizens arriving after the transition will be subject to the more stringent rules applied to non-European arrivals.

But Brussels could make continued free movement a requirement if Britain wants to retain access to the EU's single market.

Britain has agreed to honour commitments made during its EU membership, from investments to staff pensions, which will be payable as payments fall due.

Last year it put the figure at up to ?39 billion (44 billion euros, $51 billion at the time), based on Britain leaving the EU on March 29, 2019.

Three subsequent Brexit delays, during which Britain has continued paying its full membership fees, mean the final bill is likely to be higher.

Arrangements for British-run Northern Ireland in a previous draft of the deal sparked outrage among MPs, and when Johnson took office last July, he insisted on changing them.

All sides agreed on the need to avoid border checks between Northern Ireland and EU member Ireland, to avoid upsetting the fragile peace in a region plagued by violence in the 1970s, 1980s and 1990s.

Brexit supporters rejected the original plan to keep Britain under EU trade rules but the new system remains controversial.

Under the revised deal, Northern Ireland remains in Britain's customs territory, but in practice there would be a sort of customs border with the mainland.

Goods arriving and staying in Northern Ireland from non-EU countries will come under British customs rules, while those going on to the EU via the Republic of Ireland will come under the EU system.

Northern Ireland would stay aligned with the EU on some standards to ensure food, animals and permitted industrial goods can more easily cross the Irish border.

In an attempt to allay concerns about the plan, the EU and Britain agreed it would be subject to consent by Northern Ireland's devolved assembly.

A simple majority must vote for its continuance every four years, or eight years if there is sizeable cross-community support.

If the vote fails, the protocol would cease to be applied two years later, giving both sides time to try to come up with a workable alternative.