Brexit Referendum (2016): The UK Vote to Leave the European Union

The Brexit referendum was a vote held across the United Kingdom and Gibraltar on 23 June 2016 on whether the UK should remain a member of the European Union. Leave won by 51.9 per cent to 48.1 per cent, on a turnout of 72.2 per cent. The result ended David Cameron’s premiership, dominated British politics for years, and led to the UK’s departure from the EU on 31 January 2020, the first time a member state had left the bloc.

Background

Britain’s relationship with European integration had long been uneasy. The UK stayed out of the Treaty of Rome in 1957, was twice refused entry by France in the 1960s, and finally joined the European Economic Community in 1973. In the 1975 referendum, voters endorsed continued membership by about 67 per cent.

As the community deepened, opposition grew, especially within the Conservative Party. The Maastricht Treaty of 1992, which created the European Union, caused bitter divisions under John Major. The UK opted out of the euro and the Schengen area, but critics argued that EU law and institutions limited parliamentary sovereignty.

After EU enlargement in 2004, the UK was one of only three member states to open its labour market immediately to the new central and eastern European members. Net migration rose well above government forecasts, exceeding 300,000 a year by 2015, and immigration became a major political issue. The UK Independence Party (UKIP), led by Nigel Farage, won the 2014 European Parliament election in Britain with about 27 per cent of the vote.

Why the referendum was called

Under pressure from Eurosceptic MPs and the rise of UKIP, Prime Minister David Cameron promised in a speech at Bloomberg’s London offices on 23 January 2013 that a future Conservative government would renegotiate Britain’s membership and hold an in-out referendum. The Conservatives unexpectedly won a majority in the general election of May 2015, and Parliament passed the European Union Referendum Act in December.

Cameron negotiated a package of changes with the other EU leaders, agreed in Brussels on 19 February 2016. It included an emergency brake on in-work benefits for new EU migrants, an exemption for the UK from “ever closer union”, and safeguards for countries outside the eurozone. Critics dismissed the deal as modest. On 20 February Cameron announced the referendum date and said he would campaign to remain.

The question on the ballot paper was: “Should the United Kingdom remain a member of the European Union or leave the European Union?” British, Irish and Commonwealth citizens resident in the UK could vote, as could British citizens who had lived abroad for less than 15 years. Most other EU citizens living in Britain could not, and the voting age was 18.

The campaigns

The Electoral Commission designated Britain Stronger in Europe as the official Remain campaign and Vote Leave as the official Leave campaign in April 2016. Cameron, Chancellor George Osborne, most of the Cabinet, the Labour leader Jeremy Corbyn, the Liberal Democrats and the Scottish National Party backed Remain. Vote Leave was fronted by Boris Johnson, the former Mayor of London, and the Justice Secretary Michael Gove, with Labour MP Gisela Stuart, and directed by Dominic Cummings. Farage campaigned separately, alongside the Leave.EU group.

Remain focused on the economy. The Treasury, the Bank of England, the International Monetary Fund and many economists warned that leaving would cause economic damage, while US President Barack Obama said during a visit in April that the UK would be at the “back of the queue” for a trade deal. Leave supporters dismissed the warnings as “Project Fear”.

Leave’s slogan, “Take back control”, focused on sovereignty, borders and money. Its campaign bus carried the claim “We send the EU £350 million a week”, which the UK Statistics Authority called misleading because it ignored the British rebate and EU spending in the UK. Immigration was central to the Leave message, particularly that of Farage’s campaign.

On 16 June 2016 Jo Cox, a Labour MP who supported Remain, was murdered in her constituency in West Yorkshire by a far-right extremist. Campaigning was suspended for several days. In 2018 the Electoral Commission fined Vote Leave £61,000 for breaking spending rules, a finding the campaign disputed.

The result

Polls had been close, and many observers expected a narrow Remain win. Results declared through the night of 23–24 June showed a clear pattern: Leave won strongly in much of England outside the big cities and in Wales, while London, Scotland and Northern Ireland voted to remain. The chief counting officer announced the national result early on 24 June.

Around 17.4 million people voted to leave and 16.1 million to remain. Surveys after the vote found that older voters, those without university degrees and those outside large cities were more likely to vote Leave, while younger and university-educated voters leaned towards Remain, though every group was divided.

Why Leave won

Historians and political scientists have offered several overlapping explanations. Concern about immigration and a wish to restore national control over laws and borders were the reasons Leave voters most often gave in polls taken after the vote. Many also expressed long-standing dissatisfaction with the EU’s institutions, which they saw as remote and undemocratic.

Others point to economic and regional factors. Leave support was strongest in former industrial towns and coastal areas in the Midlands and north of England, places that had seen relatively little benefit from economic growth concentrated in London and the south-east. Austerity after the global financial crisis of 2008 and frustration with the political establishment are often cited as background causes.

The campaigns themselves mattered too. Vote Leave’s simple message proved effective, while Remain struggled to make an emotional case for membership. Turnout was high among older voters, who leaned heavily to Leave, and lower among the young. Claims that the result was decisively shaped by online targeting or foreign interference were investigated by parliamentary committees and regulators, but no inquiry concluded that they had changed the outcome.

Immediate aftermath

On the morning of 24 June Cameron announced that he would resign. The pound fell to its lowest level against the US dollar since 1985. After a brief leadership contest in which Johnson withdrew, Home Secretary Theresa May, who had quietly backed Remain, became prime minister on 13 July 2016, declaring that “Brexit means Brexit”.

In January 2017 the Supreme Court ruled in the Miller case that the government needed an Act of Parliament to start the withdrawal process. Parliament passed it, and on 29 March 2017 the UK formally notified the EU under Article 50 of the Treaty on European Union, starting a two-year countdown to departure.

The road to departure

May called an early election in June 2017 hoping to strengthen her position, but lost her majority and relied on the support of Northern Ireland’s Democratic Unionist Party. Negotiations centred on the financial settlement, citizens’ rights and the Irish border. The withdrawal agreement reached in November 2018 included a “backstop” to avoid a hard border in Ireland, which many MPs opposed.

The House of Commons rejected May’s deal three times in 2019, first on 15 January by 432 votes to 202, the largest government defeat in modern history. The departure date was postponed twice under May, who resigned as Conservative leader in June. Boris Johnson became prime minister on 24 July 2019 and agreed a revised deal in October that replaced the backstop with the Northern Ireland Protocol.

Johnson won a general election on 12 December 2019 with a majority of 80 seats. Parliament approved the withdrawal agreement, and the UK left the EU at 11 pm UK time on 31 January 2020. During a transition period lasting until 31 December 2020, the two sides negotiated the Trade and Cooperation Agreement, concluded on 24 December 2020, which provided for tariff-free trade in goods but ended free movement of people and membership of the single market.

Legacy

Brexit’s consequences continue to be debated. The Office for Budget Responsibility, the government’s independent forecaster, has assumed that leaving the EU will reduce the UK’s long-run productivity by about 4 per cent compared with remaining, and trade with the EU has faced new customs checks and paperwork. Supporters argue that the UK has regained control over its laws, trade policy and immigration rules, and point to its independent trade agreements with countries such as Australia and New Zealand.

The vote also put strain on the union. The Scottish National Party argued that Scotland had been taken out of the EU against its will and called for a second independence referendum. In Northern Ireland, the Protocol created checks on goods arriving from Great Britain, which unionist parties strongly opposed; it was revised by the Windsor Framework agreed with the EU in February 2023. Opinion polls since the early 2020s have generally found more people saying the decision to leave was wrong than right, while the Labour government elected in 2024 ruled out rejoining the EU, its single market or customs union.

Timeline

• 2013, 23 January: David Cameron’s Bloomberg speech promises an in-out referendum.
• 2016, 19–20 February: EU leaders agree Cameron’s renegotiation; the referendum date is announced.
• 2016, 16 June: Labour MP Jo Cox is murdered; campaigning is suspended.
• 2016, 23 June: The referendum is held; Leave wins with 51.9 per cent.
• 2016, 24 June: Cameron announces his resignation.
• 2016, 13 July: Theresa May becomes prime minister.
• 2017, 29 March: The UK triggers Article 50.
• 2019, 15 January: The Commons rejects May’s withdrawal agreement by 432 votes to 202.
• 2020, 31 January: The United Kingdom leaves the European Union.
• 2020, 31 December: The transition period ends.

Why it matters

The Brexit referendum was the first time a member state voted to leave the European Union, and it reshaped the UK’s trade, borders and politics. It exposed deep divisions of age, education and geography within Britain, strained the union between England, Scotland and Northern Ireland, and remains one of the most debated decisions in modern British history.