"This year, I am 60," said Mr Heng, adding that he would be in his mid-60s when the COVID-19 crisis is over.

"When I also consider the ages at which our first three Prime Ministers have taken on the job, I would have too short a runway should I become the next Prime Minister then," he said at a press conference announcing his decision.

"We need a leader who will not only rebuild Singapore post-COVID-19, but also lead the next phase of our nation-building efforts."

Mr Heng said: "After careful deliberation and discussions with my family, I have decided to step aside as leader of the 4G (fourth-generation) team, so that a younger leader who will have a longer runway can take over."

More at https://www.channelnewsasia.com/news/singapore/heng-swee-keat-dpm-4g-leader-step-aside-pap-pm-lee-accepts-14581784