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.
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.