An alliance of Malaysian opposition parties led by the country's 92-year-old former authoritarian leader won a parliamentary majority today in a fiercely contested general election, ending the 60-year rule of the Malay-dominated National Front.
Official results show the opposition parties, which banded together as the Alliance of Hope, surpassed the 112 seats needed for a majority in parliament.
The result is a political earthquake for Muslim-majority Malaysia, sweeping aside the Government of Prime Minister Najib Razak, whose reputation was tarnished by a corruption scandal and the imposition of an unpopular sales tax.
The opposition also made big gains in state elections including winning Johor state, where the dominant Malay party in the long-ruling National Front coalition was founded.
Mahathir in a televised address said a representative of Malaysia's constitutional monarchy had contacted the opposition to acknowledge its victory.
He said a prime minister, expected to be him, would be sworn in within a day.
Mahathir was credited with modernising Malaysia during his rule and pledged that the new government would not seek "revenge" against political opponents.
Analysts said the win by the opposition was a resounding rejection of the political status quo.
"This is a repudiation of Najib's Government from all walks of life from the very rural northern states to the more industrial southern coast," said Bridget Welsh, a Southeast Asia expert at John Cabot University in Rome.
Angered by the graft scandal, Mahathir emerged from political retirement and joined the opposition in an attempt to oust Najib, his former protege.
The US Justice Department says US$4.5 billion was looted from state investment fund 1MBD by associates of Najib between 2009 and 2014, including US$700 million that landed in Najib's bank account.
He has denied wrongdoing.
Analysts previously said the National Front might lose the popular vote but hold onto a majority in Parliament due to an electoral system that gives more power to rural Malays, the party's traditional supporters.
Faced with a reinvigorated opposition, the Government used all the levers of power to further tilt the playing field in its favour, critics and analysts said.
Redrawn electoral boundaries were rushed through parliament last month, pushing likely opposition voters into districts that already support the opposition and dividing constituencies along racial lines.
A recently passed "fake news" law was an attempt to stifle debate and criticism, opponents said.
The National Front lost its two-thirds majority in parliament in 2008 polls and lost the popular vote in 2013, though it still won 60 per cent of seats that year.