Today (24 December), Prime Minister Boris Johnson has announced that a provisional trade deal has been agreed with the European Union.
The Prime Minister said: "The deal is done."
Parliament is to be recalled next week, to vote upon the details.
Ursula Von de Leyan, the European Commission President will sign off on the deal, with ratification taking place by the EU next year. She said: "Talks were difficult."
The deal came after negotiations continued throughout the night, with fisheries being the final stumbling block.
The stock market has reacted positively to the news, with huge gains on the Pound.
Membership of the European Union has always been a contentious issue in the UK. During the 1970s and 1980s, the Labour Party was the more Eurosceptic of the two major parties, and the Conservatives the more Europhile. The 1983 Labour Party manifesto would even pledge to leave the then European Economic Community.
Under the Maastricht Treaty, the EC became the EU on 1 November 1993, reflecting the evolution of the organisation from an economic union into a political one.
Margaret Thatcher, who had previously supported the common market and the Single European Act, in the Bruges speech of 1988 warned against "a European super-state exercising a new dominance from Brussels". Conservative Eurosceptism was born.
In 2012, Prime Minister David Cameron initially rejected calls for a referendum on the UK's EU membership, but then suggested the possibility of a future referendum to endorse his proposed renegotiation of Britain's relationship with the rest of the EU. According to the BBC, "The prime minister acknowledged the need to ensure the UK's [renegotiated] position within the [EU] had 'the full-hearted support of the British people' but they needed to show 'tactical and strategic patience'."
On 23 January 2013, under pressure from many of his MPs and from the rise of UKIP, Cameron promised in his Bloomberg speech that a Conservative government would hold an in-or-out referendum on EU membership before the end of 2017, on a renegotiated package, if elected in the 7 May 2015 general election. This was included in the Conservative Party manifesto for the election.
The Conservative Party won the election with a majority. Soon afterwards, the European Union Referendum Act 2015 was introduced into Parliament to enable the referendum. Cameron favoured remaining in a reformed EU, and sought to renegotiate on four key points: protection of the single market for non-eurozone countries, reduction of "red tape", exempting Britain from "ever-closer union", and restricting immigration from the rest of the EU.
In December 2015, opinion polls showed a clear majority in favour of remaining in the EU; they also showed support would drop if Cameron did not negotiate adequate safeguards for non-eurozone member states, and restrictions on benefits for non-UK EU citizens.
The outcome of the renegotiations was revealed in February 2016. Some limits to in-work benefits for new EU immigrants were agreed, but before they could be applied, a member state such as the UK would have to get permission from the European Commission and then from the European Council, which is composed of the heads of government of every member state.
In a speech to the House of Commons on 22 February 2016, Cameron announced a referendum date of 23 June 2016, and commented on the renegotiation settlement. He spoke of an intention to trigger the Article 50 process immediately following a Leave vote and of the "two-year time period to negotiate the arrangements for exit."
After the original wording for the referendum question was challenged, the government agreed to change the official referendum question to "Should the United Kingdom remain a member of the European Union or leave the European Union?"
The UK is the first and only country to formally leave the EU, after 47 years of membership and cautious integration within the bloc after having first joined its predecessor, the European Communities (EC), on 1 January 1973.
Following a UK-wide referendum in June 2016, 52% voted in favour of leaving the EU and 48% voted to remain a member.
British membership of EU ended on 31 January 2020, beginning a period of transitional arrangements which is to end at 11pm on 31 December.