Muhyiddin Yassin, Malaysia's Shortest-serving PM

Low-profile political insider Muhyiddin Yassin had a swift and unexpected rise to Malaysia's premiership -- but his time in power was fraught with instability, and he leaves office as the country's shortest-serving leader.

He resigned on Monday after months of bitter infighting in his coalition, and with public anger growing over a worsening coronavirus outbreak.

He took power after the collapse of a reformist alliance that had swept to power at landmark polls in 2018, outmanoeuvring more charismatic rivals Mahathir Mohamad and Anwar Ibrahim.

But being appointed by the king -- rather than having won an election -- he was accused of lacking legitimacy, while his parliamentary backing was razor-thin and he struggled to tame competing factions in his coalition.

The 74-year-old leaves office after just 17 months -- the shortest-serving prime minister since Malaysian independence in 1957.

Bridget Welsh, a Malaysia expert from the University of Nottingham, said his leadership was consumed by simply trying to survive and he botched the handling of the Covid-19 outbreak.

"His mode throughout was survivalist politics," she told AFP.

"He was disconnected from the reality of Covid, the sheer scope of trauma it has inflicted on Malaysia as it worsened... He did not prepare when the country needed to be prepared."

After avoiding a first wave of infections last year, Malaysia has been hit hard this year, with Muhyiddin's government accused of moving too slowly as the highly contagious Delta variant spread nationwide.

In 1971, Muhyiddin joined the United Malays National Organisation (UMNO), the lynchpin of a coalition that ruled Malaysia for six decades until its defeat in 2018.

He was chief minister of southern Johor state, a heartland of the country's ethnic Malay Muslim majority, and later served in senior posts in central government.

Muhyiddin was named deputy prime minister in 2009 when Najib Razak was premier.

But he later fell out with Najib after criticising him over the multi-billion-dollar scandal linked to state fund 1MDB, and was sacked in 2015.

Najib was accused of looting huge sums from 1MDB, allegations that contributed to his coalition's 2018 poll defeat.

He was convicted last year and sentenced to 12 years in jail, although he remains free pending an appeal.

Muhyiddin later joined a party set up by Mahathir, and helped to oust Najib and UMNO from power.

In a volte-face typical of Malaysia's turbulent politics, he joined hands with UMNO again last year to win enough support to become premier.

But when he refused to intervene in corruption cases against some of the party's MPs, several pulled support, leaving him without a parliamentary majority.

And crucially, the influential king, Sultan Abdullah Sultan Ahmad Shah, also turned against him.