There are two ways a Conservative Party leadership contest can be triggered. The first is if the current leader resigns.
The most recent example of this was back in May 2019, when Theresa May announced her resignation as Leader of the Conservative Party and Prime Minister once her successor, Boris Johnson, was elected in July 2019.
The UK has de facto caretaker governments during general elections but not during leadership challenges. So, the prime minister in place during a leadership contest would still have all their normal prime ministerial powers.
The second is if 15 per cent of Conservative MPs write to the chair of the backbench 1922 Committee saying they no longer have confidence in the leader. A vote of no confidence is then held, with Conservative MPs voting in support or against the leader.
As of April 12 2022, there are 360 Conservative MPs, meaning 54 letters would prompt a confidence vote. Under current rules, if more than 50 per cent of all Conservative MPs (180 MPs) vote in support of the prime minister, they can stay as party leader and prime minister and no new vote can be triggered for 12 months.
A leader who loses a confidence vote is not allowed to take part in the subsequent leadership contest. The contest takes place in two stages. In the first stage, Conservative MPs put themselves forward as candidates.
All Conservative MPs then vote in a series of rounds to reduce the number of candidates until only two remain. The second stage of the contest sees the two remaining candidates put to a vote of Conservative Party members.
