Here Are the Key Players in the U.K. Election

Thursday’s general election is a pivotal moment for Britain after 14 years of Conservative Party government. Polls suggest that the center-left Labour Party is set to return to power in what would be a fundamental realignment of British politics.

Millions of voters in 650 constituencies are voting for candidates to represent them as members of Parliament. The political party that wins the most seats usually forms Britain’s next government, and that party’s leader also becomes prime minister.

To win an overall majority, a party must secure 326 seats. If the top party falls short of that, it can try to form a government with backing from other parties.

Here’s a look at the key parties and players in the race:

Conservative Party

Leader: Prime Minister Rishi Sunak

Mr. Sunak took office in October 2022, succeeding Liz Truss, whose sweeping tax cut plan spooked the financial markets and forced her out of office after just seven weeks. But Britain’s high mortgage rates and stagnant economy have persisted, and under Mr. Sunak, the Conservatives have suffered stinging losses in parliamentary special elections and elections for mayors and local councils.

Defenders of Mr. Sunak, 44, say he is a victim of the global economic headwinds coming out of the coronavirus pandemic, and argue that he deserves credit for steadying the markets. But critics say he never followed that up with a convincing strategy to recharge growth. Nor did he fulfill two other promises: to cut waiting times in the National Health Service and to stop the small boats carrying asylum seekers across the English Channel. Some say that Mr. Sunak, a onetime Goldman Sachs banker whose wife is the daughter of an Indian technology billionaire, is simply not relatable.