How do parties pick their leader?
The nutshell
A party leader is the person who runs a political party. In the UK, each party picks its own leader using its own rules. The choice is usually made by the party's members and MPs, not by the wider public.
Every fact on this page comes from Parliament's own research service and a non-partisan think tank. Each source tag — like HoC — opens where a fact comes from.
The basics
What a party leader is
A political party is a group of people who share ideas about how the country should be run. Every party has a leader. The leader speaks for the party and helps decide what it stands for. If a party wins a general election, its leader usually becomes Prime Minister. In the UK, no single law sets how a party must pick its leader. Each party makes its own rules.
How the Conservative Party picks its leader
The Conservative Party uses two stages. First, Conservative MPs (the party's Members of Parliament) vote in rounds. Each round drops the candidate with the fewest votes, until only two are left.IfG Then every party member gets a vote. A party member is someone who has joined the party, usually by paying a fee. The candidate with more than half of the members' votes becomes the new leader.HoC
How the Labour Party picks its leader
The Labour Party does it a different way. To stand, a candidate must already be a Labour MP. That MP needs support from 20 in every 100 Labour MPs. The candidate also needs backing from party groups such as trade unions, which are organisations that speak for workers.IfG Then party members and supporters vote. Each voter ranks the candidates in order of choice. To win, a candidate needs more than half of the votes.HoC
Two parties, two systems
The Conservative and Labour rules are shown here because those are the two largest parties in the House of Commons. Every other party has its own rules as well. In each case, the wider public does not vote directly for a party leader. That choice is made inside the party, by its members and MPs.
- Giving party members the final vote lets thousands of people, not only MPs, help choose the leader
- Clear party rules mean a leader can be replaced without waiting for a general election
- A high bar of MP nominations helps make sure a new leader already has support among the party's MPs
- A leader picked this way can become Prime Minister without a general election, so most voters never chose that person
- Only people who have joined and paid to be party members get the final say, and members are a small share of all voters
- The nomination and voting rules can change from one contest to the next, so the process is not always the same
The deep end6 min
The Conservative Party in detail
A Conservative leadership contest starts when the leader resigns or loses the confidence of the party's MPs. A confidence vote must be held if 15 in every 100 Conservative MPs write to the chair of the 1922 Committee, which is made up of the party's backbench MPs (the MPs who are not government ministers).HoC The contest then runs in two stages. Conservative MPs hold a series of ballots, dropping the lowest-placed candidate each time, until two names are left. The 1922 Committee sets how many MPs must nominate each candidate, and that number has changed from one contest to the next.IfG The two finalists then go to a vote of all party members, and the candidate with more than half of those votes is elected leader.HoC
The Labour Party in detail
Labour sets out its rules in the party rule book, and the party's National Executive Committee fixes the timing of each contest. To stand, a candidate must be a Labour MP with nominations from 20% of Labour MPs. Labour raised this bar from 10% in October 2021.IfG A candidate also needs nominations from party affiliates, including at least two trade unions, or from a share of local parties. Party members, plus affiliated and registered supporters, then vote. The ballot uses ranked choices, and the winner is the first candidate to pass half of the votes once lower choices are counted.HoC
What people discuss about these systems
The steps are written down, so little argument is about the process itself. Most discussion is about who should hold the final say. In both main parties, ordinary party members now cast the deciding votes, and party members are a small share of all UK voters. A leader picked this way can also become Prime Minister between general elections, with no fresh public vote. This has happened when a governing party replaced its leader partway through a Parliament. Whether members or MPs should hold more of the power is a question the parties have answered differently over time.IfG