The UK will have its next prime minister in just six days’ time following the dramatic resignation of Liz Truss.
Penny Mordaunt declared on Friday that she is running to become leader of the party.
But Rishi Sunak is thought to be the first Conservative leadership candidate to secure the backing of 100 MPs, shoring up sufficient support to be on the ballot for Monday’s vote.
On Friday night, the former chancellor’s supporters said he had amassed the necessary numbers to reach the threshold, way ahead of the deadline.
Boris Johnson was lagging behind, as was Commons Leader Mordaunt who became the first to confirm her candidacy to replace Truss as Prime Minister.
However, Johnson has told allies he is “up for it” and was flying back overnight from his holiday in the Dominican Republic to enter the race and attempt an extraordinary comeback.
Sky News photographed the ex-PM and his wife Carrie Johnson on an overnight British Airways flight back from the Dominican Republic with their children and said the MP received “one or two boos” as he boarded.
Sunak, who came second against Ms Truss in the last race six weeks ago, has around 82 public declarations, far ahead Johnson’s 48, while Mordaunt struggles on 18.
Candidates require the backing of 100 MPs in order to make the cut to become leader.
It represents a significantly higher bar than the parameters set out for the contest held in the summer.
Candidates required only 20 named Conservative MPs to enter the race then and there was a wider pool of candidates to choose from.
Chairman of the 1922 Committee Sir Graham Brady and Conservative Party chairman Jake Berry set out the rules of the contest following Truss’ resignation on Thursday.
They explained that if the party decides to put forward two candidates, there will be an expedited and binding online vote of members in order to determine the next leader.
Over the weekend, Mordaunt will undoubtedly be canvassing support among parliamentary colleagues for her campaign, while Sunak and Johnson will also be taking soundings over their chances if they are to run.
Johnson has reportedly flown back to the UK from his Caribbean holiday to attempt an extraordinary comeback after telling an ally he is “up for it”.
If the former PM does decide to run and manages to win the contest, it would be the first time since Winston Churchill in 1951 that a prime minister has returned for a non-consecutive second term in office.
He succeeded Labour prime minister Clement Attlee following the end of World War Two in 1945.
But it is Sunak who appears to be the early pacesetter as he is believed to have become the first Conservative leadership candidate to secure the backing of 100 MPs, shoring up sufficient support to be on the ballot for Monday’s vote.
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