A number of familiar names are being thrown around for PM as the UK gets ready for a week long leadership whirlwind.
Liz Truss' resignation signalled the end of the shortest term by any prime minister, followed a botched financial statement, the loss of two of her most senior Cabinet ministers and an open revolt by Tory MPs. The Conservatives are now scrambling to elect a replacement by the end of next week.
Allies of former leader Boris Johnson are pushing for him to make a return, less than two months after leaving office, while Rishi Sunak, who defeated Ms Truss among MPs in the last contest, is widely expected to stand.
READ MORE: Liz Truss resigns as Prime Minister of the United Kingdom
In an attempt to fast-track the process - and potentially eliminate the need for a vote among members - candidates will need the support of 100 of the 357 Tory MPs in Parliament to make it onto the ballot paper. In the final ballot of the last contest, Mr Sunak had 137 votes, Ms Truss 113 and Penny Mordaunt - who would also be expected to stand again - 105.
Mr Johnson still has allies both in Parliament and the party membership in general. Long-term supporter Nadine Dorries has argued he should return, along with Paul Bristow, Brendan Clarke-Smith, Andrea Jenkyns and Michael Fabricant.
The most prominent contenders for PM - other than those already mentioned - include British defence secretary Ben Wallace, Kemi Badenoch and Suella Braverman.
Sir Graham and party chairman Sir Jake Berry set out the process, with nominations for MPs open until 2pm on Monday. The first ballot of MPs will then be held between 3.30pm and 5.30pm on Monday - if there are three candidates with the required number of nominations the loser will be eliminated.
Once there are two candidates remaining, an indicative vote will be held so that the party membership know which is the preferred option among MPs. Members will be able to take part in an online vote to choose their next leader and the country's prime minister.
Some of the party's big hitters ruled themselves out, with Chancellor Jeremy Hunt focusing on calming the financial markets, James Cleverly making the case to stay on as Foreign Secretary and Michael Gove resisting another run.
Commons Leader Penny Mordaunt was in the Chamber as news of Ms Truss's resignation broke and told MPs she would "keep calm and carry on". Justice Secretary Brandon Lewis has been encouraged to stand by colleagues, allies said.
Labour leader Sir Keir Starmer demanded a general election "now" so that the nation can have "a chance at a fresh start".
Sir Keir said: "The British public deserve a proper say on the country's future. They must have the chance to compare the Tories' chaos with Labour's plans to sort out their mess, grow the economy for working people and rebuild the country for a fairer, greener future."
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