The 1922 Committee has a 12-member executive committee, the chairman of which must oversee any election of a new party leader, or any vote of confidence for the current one; such a vote can be triggered by 15 percent of Tory MPs writing a letter to the chairman asking for such a vote. This was invoked most recently on October 28, 2003, when 25 MPs requested a vote of confidence in Iain Duncan Smith by writing to the chairman, Sir Michael Spicer. Duncan Smith lost the vote the next day.
The committee was formed in 1923, but takes its name from the 1922 General Election. Contrary to popular opinion, it does not come directly from a meeting in 1922 when Conservative MPs (successfully) demanded that the party withdraw from the coalition government of David Lloyd George. Many new Tory MPs (enough for an overall majority) were elected in the general election that this act triggered, and they formed the 1922 Committee but the founder MPs were not the ones who had taken the decision to break up the coalition government. However the membership of the Committee was subsequently expanded to include virtually all MPs in the party and the name serves as a reminder of the power of the backbench MPs.
The analogous body for the Labour Party is the Parliamentary Labour Party.