UK general election: how does it work, when are the results and why does it matter to the world?

The UK general election takes place on 4 July. Here we look at how elections work in the UK and what could happen this time.

How do general elections in the UK work?

The UK – that is England, Wales, Scotland and Northern Ireland – is divided into 650 constituencies, a geographical electoral division or district.

Voters cast a ballot for the person they want to represent their constituency in the UK Houses of Parliament. Candidates run as members of political parties with the key parties including: the Labour party, the Conservative party, Liberal Democrats, Scottish National party, Green party, Reform UK, Sinn Féin and the Democratic Unionist party. Candidates can also run as independents.

The candidate with the most votes in that constituency is elected as a member of parliament (MP).

The party with the most MPs then forms a government if it has a majority (at least 326 seats).

How many people can vote in the UK? And how many will?

The most recent figures from the Office for National Statistics (ONS), the UK’s public body for official data, show there are about 49 million people registered to vote in the UK.

Eligibility rules dictate that voters must be registered to vote in their constituency and must be 18 years old or older on polling day. Voters must be either a British citizen, a qualifying Commonwealth citizen or a citizen of the Republic of Ireland. Prisoners cannot vote. Voting is not compulsory.

In 2019, 67.3% of people who were registered to vote cast a ballot, down by 1.5 percentage points from 68.8% in 2017. It was the first time in four successive general elections that turnout had fallen.

The lowest turnout at a general election since the second world war was in 2001 when it slumped to 59.4%, while the highest since the war was 83.9% in 1950, according to figures compiled by the House of Commons Library.

How do you vote in the UK?

In the UK, you can vote in person at a polling station, which is usually in a public building, such as a school or community centre. Polling stations are open from 7am to 10pm on the day of the election.

Voters are handed a ballot paper on which they put a cross next to the candidate they wish to support.

It is possible to register to vote by post in the UK, although this was the subject of some controversy in the final days of the election campaign.

In the UK, it is also possible to apply for a proxy vote if you are going to be away on polling day or have a disability or medical issue.

Since May 2023, voters have been required to take photo ID, such as a driving licence or passport, with them to polling stations in the UK.

When will the results be announced?

The first indication of the results is the well-respected exit poll, developed by the statisticians Prof John Curtice and David Firth. The results of the poll, which are published at 10pm on election night, are considered to have a good record of accuracy and are based on the votes cast in a mock ballot by people in about 130 polling stations.

It is the first moment of election night to produce a tangible sense of where the voters stand. The prediction will be shared by the broadcasters BBC, ITV and Sky. In the past five general elections, the margin of error has ranged between 1.5 and 7.5 seats.

After this, it is a matter of waiting for individual constituencies to announce the results of their counts. The first result is expected about 11.30pm with more trickling in until about 3am. About 440 of the 650 seats will be declared over the following two hours. Typically, all seats are in by 8am on Friday.

The results will be announced at the count centres and reported by media throughout the night. Unlike in the US, media outlets do not “call it” for any particular party. It will become clearer as the night progresses if any single party has surpassed the 326 seat mark required for a majority.

What do the opinion polls say?

For the last year, the polls have consistently suggested a clear victory for Labour, ending 14 years of Conservative party rule.

The Guardian’s election poll tracker as of Tuesday 2 July showed Labour with a 20-point lead over the Conservatives (40.7% compared with 20.7%). This is an average of polls over a moving 10-day period.

This would translate into 428 seats for Labour, up from 203 in the previous parliamentary term, and the Conservatives would secure 127 seats, down from 365 in the last term. This would give the Labour party a majority of 102 seats.

Who are the party leaders?

Rishi Sunak is the leader of the Conservative party and incumbent prime minister of the UK. He has been leader since October 2022. His constituency as an MP is Richmond, in Yorkshire, a county in the north of England, which he has represented since 2015. Sunak became PM after Liz Truss’s disastrous short-lived tenure, positioning himself as a “safe pair of hands” leader after a period of chaos at the top of government. Prior to politics, the privately educated Oxford university graduate worked for investment banks and hedge fund firms.

Keir Starmer has led the Labour party, and the official opposition, since April 2020. He took up the leadership role after Jeremy Corbyn’s leftwing vision failed to convince voters. First elected as an MP in 2015 for the Holborn and St Pancras constituency in north London, Starmer previously served as shadow Brexit secretary and shadow immigration minister. Training as a lawyer at Leeds and Oxford universities, Starmer’s legal career peaked as director of public prosecutions, the head of the criminal prosecutions body in England and Wales.

Other party leaders include Ed Davey for the Liberal Democrats, John Swinney for the SNP, Carla Denyer and Adrian Ramsay for the Green party and Nigel Farage for Reform UK.

Why does this election matter?

The election has particular significance as it follows a particularly turbulent time in UK politics. Prime minister David Cameron’s programme of austerity, the Brexit referendum in 2016, the post-Brexit negotiations that toppled Theresa May, the rise and fall of Boris Johnson triggered by the Partygate scandal in which Johnson and other senior figures were found to have breached UK Covid rules during the pandemic, and Liz Truss’s record-breaking 50-day stint as PM have all taken place during a 14-year period that has been characterised by many as chaotic.

Even during the election campaign, scandal haunted the Conservative party when it emerged senior figures had been accused of using insider knowledge of the election date to place bets.

The polls suggest voters are preparing to back the centre-left Labour party, and at the same time populists Reform UK are also gathering momentum.

This heady mix has positioned this general election as one of the most hotly anticipated in many years.