Anwar and Mahathir have a notoriously stormy relationship but they reconciled ahead of the 2018 polls, and Mahathir has repeatedly promised to hand over power to his former foe.
The bid appeared to have fizzled out by early Monday, however -- before Mahathir's office announced he had "sent a resignation letter as prime minister of Malaysia" to the king at 1:00 pm.
What would happen next was far from clear, however.
Anwar was due to meet the king Monday afternoon. While the monarch's role is largely ceremonial, he confirms the appointment of the country's prime minister and Anwar could be hoping to persuade him that he has enough support from MPs to form a government, observers said.
However, Mahathir's party Bersatu also announced it was leaving the "Pact of Hope" coalition -- suggesting they could be making their own attempt to form a government.
Earlier, two of Anwar's rivals from his People's Justice Party, Mohamed Azmin Ali and Zuraida Kamaruddin -- seen as key figures in leading the bid to form a new government and block his ascent -- were sacked, the party announced.
Anwar had teamed up with former nemesis Mahathir ahead of the 2018 elections to oust the government of Najib Razak, who had become embroiled in the massive 1MDB graft scandal.
They led an alliance to an unexpected victory against a coalition that had ruled Malaysia uninterrupted for over six decades, and Mahathir agreed to eventually hand power to Anwar.
But Mahathir, in his second stint as premier after first holding the role from 1981 to 2003, has repeatedly refused to say when he will transfer power, stoking tensions within the four-party coalition.
The alliance's popularity had plummeted as it was accused of failing to raise living standards and protect the rights of the ethnic Malay Muslim majority, and it lost a string of local polls.
According to reports, the proposed new government aimed at blocking Anwar would have included Mahathir's party, the United Malays National Organisation -- the party of scandal-tainted ex-leader Najib -- and a hardline Islamist group.
Many were angry, however, that the democratically elected government, which came to power partly on a pledge to push through much-needed reforms, could be replaced without an election.
The people "will not agree to or cooperate with any 'backdoor' government formed out of the selfish, self-preservation agenda of certain MPs", said a statement from a group of leading activists and academics.
Some called for a snap poll, although politicians appeared to be trying to form a new government without holding an election.
Business Standard has always strived hard to provide up-to-date information and commentary on developments that are of interest to you and have wider political and economic implications for the country and the world. Your encouragement and constant feedback on how to improve our offering have only made our resolve and commitment to these ideals stronger. Even during these difficult times arising out of Covid-19, we continue to remain committed to keeping you informed and updated with credible news, authoritative views and incisive commentary on topical issues of relevance.
We, however, have a request.
As we battle the economic impact of the pandemic, we need your support even more, so that we can continue to offer you more quality content. Our subscription model has seen an encouraging response from many of you, who have subscribed to our online content. More subscription to our online content can only help us achieve the goals of offering you even better and more relevant content. We believe in free, fair and credible journalism. Your support through more subscriptions can help us practise the journalism to which we are committed.
Support quality journalism and subscribe to Business Standard.