What Is a Party Whip? Chief Whips, Three-Line Whips and Free Votes

A party whip is an MP or peer appointed by their party to make sure its members turn up and vote the way the party leadership wants. The word also has two related meanings: the written instructions whips send out about forthcoming votes, and membership of the parliamentary party itself, which is why an MP can "have the whip" or "lose the whip".

The name comes from hunting. A "whipper-in" was the huntsman's assistant who kept the hounds from straying from the pack.

What whips do

Whips are often pictured as enforcers, and keeping discipline is part of the job. But much of their work is organisation and communication.

• Counting votes. Whips find out how members intend to vote and warn the leadership when a rebellion is brewing. The Chief Whip advises the Cabinet, or the Shadow Cabinet, on whether legislation is likely to pass.
• Passing messages both ways. They explain party policy to backbenchers and carry backbench concerns back to the leadership.
• Organising business. They help manage the parliamentary timetable and distribute information about it.
• Working with other parties. Whips of different parties deal with each other through what are known as "the usual channels".
• Pairing. When an MP has to be away, whips can pair them with an absent MP from the other side, so the two missing votes cancel out.
• Appointments. They put forward party members for select committees and influence frontbench jobs, reshuffles and office allocations, which gives them rewards to offer for loyalty.

The Chief Whip and the whips' office

Each party in the Commons has a Chief Whip who runs its whips' office. The government's Chief Whip is customarily appointed Parliamentary Secretary to the Treasury, a post that carries a place in Cabinet. The official residence is 12 Downing Street, though the office itself is at 9 Downing Street.

Other government whips hold old titles that link them to the Treasury or the royal household:

• the Deputy Chief Whip is Treasurer of HM Household;
• the next two most senior whips are Comptroller and Vice-Chamberlain of HM Household;
• most of the remaining whips are Lords Commissioners of the Treasury;
• assistant whips, and opposition whips, generally do not receive these appointments.

In the House of Lords, the Government Chief Whip is Captain of the Honourable Corps of Gentlemen-at-Arms, and the deputy is Captain of the Yeomen of the Guard. The Opposition Chief Whip in the Commons receives an additional payment on top of an MP's salary, because the role leaves no room for another job.

The weekly whip: one, two and three lines

At the start of each week, each party's whips send their MPs a document, itself called "the whip", listing the business coming up. Each vote is marked by how important it is to the party, shown by underlining it once, twice or three times. That is where the terms one-line, two-line and three-line whip come from.

Type	Meaning
One-line whip	MPs are asked to attend, but it is not required.
Two-line whip	Attendance is necessary, and MPs must ask permission to miss the vote. This level is now used rarely.
Three-line whip	Attendance is essential, and permission to be absent is rarely granted. Defying it is a serious breach of party discipline.

The weekly whip is a party document, not an official one: it is not published, and neither it nor the hand signals whips use in the chamber during a vote are recorded in Hansard. A government can raise the stakes further by declaring a vote to be a matter of confidence, meaning that losing it would lead to the government's resignation.

Free votes

Sometimes a party decides not to issue a whip on a vote. This is a free vote, and members vote according to their own judgement. Free votes have traditionally been used for matters of conscience, such as fox hunting and assisted dying. They are one of the few occasions when frontbenchers can take an independent line despite the normal rule of collective responsibility.

Losing the whip

When a party withdraws the whip, the MP stops representing the party in Parliament and sits as an independent. A party cannot remove someone from Parliament, since the MP was elected by their constituency, but it can stop them sitting with the party and remove them from any ministerial post. In effect, the MP is expelled from the party.

The whip is usually withdrawn when an MP defies a three-line whip or faces allegations of serious misconduct. Two examples from the public record show both governing parties using it:

• in September 2019, 21 Conservative MPs lost the whip after voting against the government over the Benn Act, legislation on the UK's departure from the European Union;
• in July 2024, seven Labour MPs had the whip suspended after a vote on the two-child benefit cap.

The whip can be restored later. In November 2025, for example, it was restored to four of the Labour MPs suspended in 2024.

Whips in other parliaments

• House of Lords: discipline is looser than in the Commons, and Lords whips do not use pairing. They play a larger front-bench role, answering questions and taking bills through the chamber.
• United States: both houses of Congress have majority and minority whips. The House whip was created in 1897. Whips there have less influence than in the UK, and no one, members of Congress included, can be expelled from a party.
• Canada: the whip's office prepares vote sheets setting out the party's position on each bill or motion, and also assigns offices and schedules the party's speakers.
• Australia: whips are recognised for parliamentary purposes but hold no official office. They keep a "pairs book" and ensure members attend votes. Liberal Party whips are appointed by the party leader, while Labor whips are elected by the caucus.
• Ireland: the government chief whip is normally a Minister of State at the Department of the Taoiseach and attends cabinet meetings.
• South Africa: the whip system inherited from British rule was kept even though the country elects its parliament by proportional representation; one senior post is Chief Whip of the Majority Party.

For the role parties play more generally, see what is a political party.