Malaysia's Mahathir Mohamad will run for prime minister on behalf of the former ruling coalition, he said on Saturday, less than a week after he quit and plunged the country into political turmoil.

That meant that Mahathir, who as interim prime minister is the world's oldest government leader at 94, has reunited with on-off ally and long-term rival Anwar Ibrahim, 72, resuming a pact that swept their coalition to a surprise election victory in 2018.

The move averted a showdown between men whose struggle has shaped Malaysian politics for two decades — but risked sidelining both and returning to power the corruption-tarnished former ruling party that they had defeated.