"The Council has adopted, by written procedure, the decision on the conclusion of the withdrawal agreement on behalf of the EU," the Council of the European Union said in a press release.
After that, a transition period will begin, during which the sides will negotiate their post-Brexit relations.
The United Kingdom missed the Brexit deadline twice: in March and in October 2019. This led to early parliamentary elections in December that brought victory for the Conservatives who got 48 seats in the House of Commons. The Labour lost 60 seats, and this prompted party leader Jeremy Corbyn to announce his plans for resignation.
In 2016, the British people voted in a referendum to leave the EU. This was followed by years of debates amid fears that Scotland could seek to leave the UK to remain in the EU and concerns over the future of the border between Ireland and Northern Ireland.