The last election for the leader of the Conservative Party was held between 13 July and 5 September 2022. Liz Truss was elected leader with the support of 57.4% of voting members, defeating Rishi Sunak.
As the Conservative Party is currently in government, Liz Truss became Prime Minister on 6 September 2022. She replaced Boris Johnson, who announced his resignation in July.
Conservative Party leadership elections have two stages. In the first, successive ballots of Conservative MPs narrow the list of candidates – who must be sitting Conservative MPs - down to two. The winner is then chosen in a ballot of the membership.
While the Conservative Party Constitution dictates that an election among the membership must always be held, the process by which candidates are selected to be presented to the membership is determined by the 1922 Committee of backbench Conservative MPs in consultation with the Conservative Party Board. These rules are not publicly available, and are announced at the beginning of every leadership contest by the chair of the 1922 Committee (currently Graham Brady).
If a Conservative leader resigns, this triggers a contest for a new party leader. The outgoing leader is not eligible to stand in the ensuing election.
If the resigning leader is prime minister, he or she is normally expected to stay in post until a new leader is elected, as Theresa May did in 2019 and David Cameron did in 2016. The UK has de facto caretaker governments during general elections but not during leadership challenges. This means that, during a leadership challenge, the government and civil service continue to function without change. This caused some controversy in 2022, when Boris Johnson remained in post as prime minister following the resignation of dozens of ministers in order to allow a leadership contest to take place.
If the prime minister does not not wish to remain in post, they could resign as prime minister and recommend that the King appoint somebody else as prime minister until the Conservative Party had chosen a new leader. That person would presumably be another Conservative MP and probably a member of the Cabinet. They would be prime minister until the leadership contest is over. This would be a very unusual situation and unprecedented in modern times. There is no such thing as a “temporary” or “interim” prime minister in the UK. Anyone the monarch appoints as prime minister has all the powers and authority of the office.
It might be expected that if this were to happen such a person would rule themselves out of the leadership contest, and it is not clear how they would be chosen.
Under current party rules, Conservative Party MPs can initiate a no confidence vote in the leader when 15% (54 MPs) of Conservative MPs write to the chair of the party’s 1922 Committee (a committee representing backbench Conservative MPs).
The no confidence vote is scheduled by the chair of the 1922 Committee in consultation with the party leader. MPs then vote in support or against the leader. This can happen quickly. For example, the no confidence vote in Theresa May was held on 12 December 2018, the day after she was informed that the 15% threshold had been reached. May needed 159 MPs to support her to stay in office, and won the vote by 200 to 117. On 6 June 2022, Boris Johnson faced a confidence vote, which he won by 211 votes to 148 (59% to 41%). He then announced he was stepping down a month later.
Under current rules, if more than 50% 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.
If the leader lost the confidence vote among Conservative MPs, they would not be able to stand again – allowing any other Conservative MP to stand for the party leadership.
Before 1965, leaders of the Conservative Party ‘emerged’ after discussion among MPs – rather than via an election.
However, in 1965, then party leader Alex Douglas-Home introduced a process according to which future leaders would need to be elected by a ballot of Conservative MPs. To succeed in the first round, a candidate would have to obtain more than 50% of the vote and be 15% clear of the second-place candidate. If no-one managed this, the election would continue until one candidate gained more than 50% of the votes.
The current rules were introduced in 1998 by William Hague, then leader of the Conservative Party, after the party’s general election defeat in 1997.
There is no other formal method by which to initiate a leadership challenge. However, there are ways for the rest of the party to express a lack of confidence in the leader.
The National Conservative Convention (NCC) is a body representing the voluntary wing of the party, made up of association chairs, area and regional officers and specialised groups (such as Young Conservatives and the Conservative Women’s Organisation). In April 2019, more than 65 Conservative Association Chairmen signed a petition calling for an extraordinary general meeting of the NCC - in which concerns about Theresa May’s leadership of the Conservative Party were raised.