Sabah Umno leader Salleh Said Keruak has raised the startling prospect of Dr Mahathir Mohamad becoming prime minister for the third time with a third political coalition.

“In politics, age and ambition have no limits. Therefore, do not underestimate the will of an old man,” he said in reference to the 98-year-old politician.

The basis for Salleh’s bold prediction is...