Here are the rules for Conservative party leadership election now only one candidate is left

Theresa May is the sole candidate after Andrea Leadsom dropped out

Home Secretary Theresa May officially launches her campaign to become prime minister at Austin Court in Birmingham (PA)

Theresa May is the only candidate remaining in the Conservative party leadership race after Andrea Leadsom dropped out on Monday.

The rules of the leadership contest, as laid out in the Tory party constitution, will dictate what happens next.

The relevant section of the rules, in schedule 2, say:

“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.”

It adds:

“If there is only one candidate at the time laid down for the close of nominations, that candidate shall be declared Leader of the Party.”

1922 Committee chair Graham Brady confirmed shortly after Ms Leadsom's resignation that Ms May would be elected unopposed – subject to formal approval by him and the Conservative Party board.