Up to 6 p.m. on Thursday London time, Rishi Sunak, the former Indian origin Chancellor of the Exchequer in the British government, had not indicated either way if he will stand in the contest to be Prime Minister.

The Daily Telegraph newspaper, however, reported he will stand. He has emerged as the bookmakers' favourite.

Meanwhie, for the first time in British history, a Prime Minister could be selected by a political party by online voting. This though will only happen in the event of a run-off between two candidates. In other words, if the ruling Conservative party MPs decide on a consensus candidate, there will be no confirmatory online vote extended to rank and file members.

The Conservatve parliamentary party set a high bar for a candidate to qualify to contest - support of at least 100 MPs. Aspirants have to throw their hats into the ring by 2 p.m. on Monday London time.

If only one candidate crosses the threshold, there will automatically be a new Prime Minister the same day. If there are more, then there will first be a vote by MPs until the list is watered down to two, before party members get a say. This process will be completed by October 28.

Realistically, there can at most be three contestants, given the minimum entry mark of 100. Conservative MPs in the House of Commons number an estimated 357.

The emergency election of a new Prime Minister was necessitated by the resignation of Liz Truss on Thursday after only 45 days in office. Truss defeated Sunak in a head-to-head in the summer.