Krdytkyu

This question as quite hypothetical as I don't believe it will come to pass, but…

There is an ongoing situation in which Theresa May, Leader of the United Kingdom Conservative Party and Prime Minister of the United Kingdom of Great Britain and Northern Ireland, is facing a leadership challenge. If she loses, she cannot take part in the subsequent leadership election.

It has been said that currently, the Prime Minister faces a rather impossible job. I can imagine many good reasons to not want the job. In theory, if there is a leadership election but no candidates (or no candidates with enough support to get their name on the ballot), what happens next? Will the position remain vacant?

Conservative party rules require that the Leader is an MP. The party's constitution only requires that "There shall be a Leader of the Party, drawn from the Members of Parliament" It doesn't give any remedy in case no MP is willing to stand. It would be a big problem for the party, but no laws would be broken. The existing Leadership would probably remain in a caretaker role until someone is willing to stand.

In terms of the constitution, the Prime Minister and Cabinet must nominate their successor. Normally this would be either the next leader of her party, or the leader of the opposition (in case that she had lost a vote of confidence and the leader of the opposition had been able to form a coalition).

In the exceptional circumstances of there being nobody willing and able to form a government then surely MPs would have no confidence in the government, and a new election would be held. These would not be business as normal, and would probably lead to a collapse of the party. For all sorts of reasons, this isn't going to happen.

The Prime Minister is appointed by the Queen on the recommendation of the outgoing PM. Under normal circumstances, this is relatively straightforward: it's the leader of the party which, alone or in a coalition or other agreement, can command a majority in the Commons (or failing that, is likely to survive a confidence vote).

However, in theory (and, in the distant past, in practice), the Queen could appoint anyone to the post if they have enough support in Parliament. There's even no requirement for the PM to be an MP (there have been a number of PMs who sat in the House of Lords), though it's unthinkable that that would be allowed these days.

Also, the convention is that an outgoing PM does not resign until a successor is in place. So for example, Gordon Brown remained as caretaker PM for 5 days after losing the 2010 election, until it was clear that David Cameron would head a coalition government.

In practice

The present rules state that the Conservative Parliamentary Party will select (from their own membership) two candidates that will then be voted on by the Conservative Party's general membership. For the record, it doesn't say that they have to be willing(!).

The current rules for electing the leader of the Conservative Party were
introduced in 1998. The system gives every member of the Conservative Party a say in the election of the leader. In brief, the election system consists of two stages:

• Conservative Members of Parliament select a choice of two
candidates to present to the membership of the whole Party

• Party members vote, on a "one member one vote" basis, for their
preferred candidate from a shortlist of two

_{^{HoC Briefing Paper: Leadership elections: Conservative Party}}

It is simply inconceivable, given that there are potentially 315 candidates for the role, several of whom have stood in prior elections or expressed that they would like to become leader, that no two members would be interested in becoming leader of the party. In extremis it can be assumed that pressure would be brought to bear by the Whips Office, the 1922 Committee and the Chairpeople of the MP's own local associations to essentially force some members to stand.

In theory

The Constitution of the Conservative Party makes allowance for a change to the rules for the election of leaders. This requires only a simple majority of the Executive Board of the 1922 Committee. They could, for example, allow non-MPs to offer themselves for the leadership (such as the 248 Conservative Peers of the Realm, MSPs or AMs).

Upon the initiation of an election for the Leader, it shall be the
duty of the 1922 Committee to present to the Party, as soon as
reasonably practicable, a choice of candidates for election as Leader.
The rules for deciding the procedure by which the 1922 Committee
selects candidates for submission for election shall be determined by
the Executive Committee of the 1922 Committee after consultation of
the Board.

The 1922 committee could then nominate a single candidate who would then immediately become leader (although this would be politically unpalatable)

In the event of there being only one valid nomination at the close of
nominations prior to the first ballot being held by the Parliamentary
Party for the election of the new Leader, the election of the nominee
may if so ordered by the Board be ratified by a ballot of the Party
Members and Scottish Party Members to be held within one month of the
close of nomination.