Win = take enough constituency seats to command a majority in the Houses of Parliament, for a member of the party to take the role of Prime Minister, to have their request to form a government accepted by the monarch.

Next UK General Election = the first general election following 12th December 2019, expected 2024 but may occur any time before February 2025. Close date will be amended to reflect close of polls on election day when the date is announced.

If the election results in a coalition government then the winning party for the purpose of this question will be the party of the Prime Minister chosen following the election. If the election results in a hung parliament unable to form a government, leading to another General Election, then this market will resolve N/A.