British Indian Rishi Sunak's best chance of becoming Prime Minister of the UK lies in no other candidate mustering the support of 100 ruling Conservative party MPs — a minimum condition set by the 1922 Committee, authorised to conduct the election, as a qualifying mark.
That would mean a no contest for the leadership and he would automatically get the top job. On the other hand, if either former Prime Minister Boris Johnson or Penny Mordaunt, who was leader of the House of Commons under Liz Truss, who threw in the towel as premier on her 45th day in office, crosses the threshold of support from 100 MPs, then a confirmatory vote by the wider membership of the Conservative party could be an uncertain prospect for Sunak.
He lost to Truss at this stage in the summer.
The BBC reported on Saturday morning Sunak 'is set to officially enter the race to become the UK's next Prime Minister'. It had also been indicating since Friday night that he was 'the first to receive the support of 100 Conservative MPs'.
Johnson, who with his family was holidaying in the Caribbean island of Dominica, flew back to London on economy class on Saturday morning.
There is growing speculation that he will run. But according to media reports on Saturday afternoon he had not obtained the endorsement of 100 MPs.
Mordaunt formally announced her candidature in Friday evening. But was also said not to have managed the backing of sufficient fellow lawmakers.
Mordaunt was third in that competition earlier this year which was won by Truss.
Neither Sunak nor Johnson have officially declared their intention to contest the leadership election, with Leader of the Commons Penny Mordaunt the only candidate to formally announce her candidacy so far.
However, the former Finance Minister has taken a comfortable lead with some heavyweight Tory ministers and MPs from different factions of the Tory party throwing their weight behind him and the betting odds also continuing to rise in favour.
Former Deputy Prime Minister Dominic Raab told the BBC, "I think he is the best placed candidate to provide some stability, to provide confidence for the millions of workers and businesses up and down the country,” he said.