1. Introduction: Referendums and the UK Constitution
A referendum is a direct vote in which the whole electorate, or the electorate of a particular nation or region, is asked to decide a single question, usually by choosing between two options.
The UK constitution is uncodified and rests on the doctrine of parliamentary sovereignty, meaning that legally Parliament remains free to legislate as it wishes and referendum results are not, in themselves, legally binding on Parliament unless a specific Act says otherwise.
In practice, however, referendum results on major constitutional questions have generally been treated by governments as politically decisive.
Before 1997, referendums played almost no part in UK politics. There was one UK-wide referendum, held in 1975 on continued membership of the European Economic Community, and two devolution referendums in 1979 on proposed assemblies for Scotland and Wales (the Scottish result narrowly failed to clear a required threshold and the Welsh proposal was rejected outright).
From 1997 onwards, referendums became a recurring feature of UK political life, used first to authorise the devolution settlements created by the incoming Labour government, and later to decide questions of electoral reform, Scottish independence and continued EU membership.
2. Chronology of Major Referendums Since 1997
The devolution referendums, 1997 to 1998
Tony Blair’s Labour government elected in May 1997 had committed to a programme of constitutional reform, including devolved government for Scotland, Wales, Northern Ireland and London. Referendums were used to authorise each of these changes before the relevant legislation was passed.
- Scotland, 11 September 1997: two questions were asked, on whether there should be a Scottish Parliament and whether it should have tax-varying powers. Both were carried, with 74.3% and 63.5% voting yes respectively, on a turnout of 60.4%.
- Wales, 18 September 1997: voters were asked whether there should be a National Assembly for Wales. The result was a narrow yes, 50.3% to 49.7%, on a turnout of 50.1%.
- London, 7 May 1998: a referendum on creating a Greater London Authority and a directly elected Mayor of London returned a 72.0% yes vote, on a turnout of 34.1%.
- Northern Ireland, 22 May 1998: voters were asked whether they endorsed the Belfast, or Good Friday, Agreement, which established the Northern Ireland Assembly and a power-sharing executive. The result was 71.1% in favour, on a turnout of 81.1%, the highest of any of the 1997 to 1998 referendums.
The Scotland Act 1998, Government of Wales Act 1998, Northern Ireland Act 1998 and Greater London Authority Act 1999 subsequently gave legal effect to these results.
A statutory framework: the Political Parties, Elections and Referendums Act 2000
The Political Parties, Elections and Referendums Act 2000 (PPERA) created a statutory framework that has applied to referendums held since then.
It introduced spending limits for campaigners, provision for one lead campaign organisation to be designated on each side of a question, and oversight of referendum conduct and finance by the newly created Electoral Commission.
Further devolution and regional referendums, 2004 to 2012
- North East England, 4 November 2004: voters rejected a proposed elected regional assembly by 77.9% to 22.1%, on a turnout of 47.7%. This result ended the wider Labour government plan to extend elected regional government across England.
- Local mayoral and council tax referendums: under the Local Government Act 2000 and later the Localism Act 2011, a number of English local authorities have held referendums on whether to adopt a directly elected mayor, with mixed results, and the Localism Act 2011 also introduced a requirement for a local referendum before a council can implement a council tax increase above a threshold set annually by central government.
- Wales, 3 March 2011: voters were asked whether the National Assembly for Wales should gain full primary law-making powers in its devolved areas without needing separate Westminster approval for each measure. The result was 63.5% yes, on a turnout of 35.4%.
The Alternative Vote referendum, 5 May 2011
Under the terms of the 2010 Conservative-Liberal Democrat Coalition Agreement, a UK-wide referendum was held on whether to replace First Past the Post with the Alternative Vote for electing MPs to the House of Commons.
The proposal was rejected by 67.9% to 32.1%, on a turnout of 42.2%.
The Scottish independence referendum, 18 September 2014
Following the Scottish National Party’s majority in the 2011 Scottish Parliament election, the UK and Scottish governments concluded the Edinburgh Agreement in 2012, and the Scottish Independence Referendum Act 2013 authorised a referendum on the question, ‘Should Scotland be an independent country?’
The result was 55.3% no to 44.7% yes, on a turnout of 84.6%, the highest recorded in any UK-wide or national referendum or election since the introduction of near-universal suffrage.
In the closing days of the campaign, the leaders of the three main Westminster parties jointly pledged further devolved powers for Scotland in the event of a no vote, a commitment that fed into the Scotland Act 2016.
The European Union membership referendum, 23 June 2016
A referendum on the UK’s membership of the European Union had been promised by David Cameron in a 2013 speech and repeated in the Conservative Party’s 2015 general election manifesto.
It was authorised by the European Union Referendum Act 2015. The question asked whether the UK should remain a member of or leave the EU.
Leave won with 51.9% of the vote to Remain’s 48.1%, on a turnout of 72.2%.
The result varied markedly by nation: England and Wales recorded majorities for Leave, while Scotland and Northern Ireland recorded majorities for Remain.
David Cameron resigned as Prime Minister the day after the result, and the UK formally left the EU on 31 January 2020, with the post-exit transition period ending on 31 December 2020.
3. Summary of Major UK Referendums Since 1997
| Date | Referendum | Result | Turnout |
| 11 Sept 1997 | Scotland: Scottish Parliament and tax-varying powers | Yes 74.3% / Yes 63.5% | 60.4% |
| 18 Sept 1997 | Wales: National Assembly for Wales | Yes 50.3% | 50.1% |
| 7 May 1998 | London: Mayor and Greater London Authority | Yes 72.0% | 34.1% |
| 22 May 1998 | Northern Ireland: Belfast (Good Friday) Agreement | Yes 71.1% | 81.1% |
| 4 Nov 2004 | North East England: elected regional assembly | No 77.9% | 47.7% |
| 3 March 2011 | Wales: full law-making powers for the Assembly | Yes 63.5% | 35.4% |
| 5 May 2011 | UK-wide: Alternative Vote for general elections | No 67.9% | 42.2% |
| 18 Sept 2014 | Scotland: independence from the United Kingdom | No 55.3% | 84.6% |
| 23 June 2016 | UK-wide: membership of the European Union | Leave 51.9% | 72.2% |
Figures are the official results published by the returning authorities and the Electoral Commission; minor discrepancies of a fraction of a percentage point appear in some published sources owing to rounding and rejected ballots.