The doctor, who served 22 years as the country's leader before retiring in 2003, is determined to topple the party he once led -- and in his quest to do so, has joined forces with his arch nemesis, former deputy prime minister Anwar Ibrahim, whom he once jailed for corruption and sodomy.
The former leader told CNN in an exclusive interview that his return to the political spotlight is down to his determination to oust the current prime minister, Najib Razak.
"I think it's a job I have to do. I cannot accept this country being destroyed by selfish people who only think about themselves... who steal money," Mahathir told CNN last week.
Malaysia's next elections will be held before August 2018, with many people widely expecting it to occur sometime in March.
"They [the political opposition parties] have not been able to get rural Malay votes," Mahathir said, explaining the rationale behind the opposition's decision to welcome him into their pact.
"They had a majority of popular votes in 2013, but they were not able to get [the] constituencies with Malay voters. They think I can."
Mahathir has made a bad habit of sniping at those who stepped into his shoes as prime minister. Post-retirement, Mahathir criticized his anointed successor Abdullah Ahmad Badawi
incessantly from the sidelines. But that is nothing compared to the energy and viciousness with which he has torn into Najib.
Mahathir, who said he attacked his successors because 'they were doing wrong things,' told CNN he doesn't mind "being used by the opposition" to oust Najib, who for years has been embroiled in accusations that hundreds of millions of dollars were stolen from state investments.
The US Justice Department filed lawsuits in 2016, amended earlier this year, to recover more than $1.7 billion that prosecutors said were laundered through a Malaysian sovereign wealth fund headed by Najib.
Besides the United States, several other countries are investigating state investment fund 1Malaysia Development Berhad (1MDB), which Najib founded. US justice officials said that between 2009 and 2015, more than $3.5 billion from 1MDB was misappropriated
by high-level officials of the board and associates.
Najib has been accused of siphoning money from the investment fund after $681 million was transferred into his accounts. He has consistently denied any wrongdoing and said the money was donated by a member of the Saudi royal family.
The 1MDB scandal, rising costs of living and a growing rift among the country's multiracial, multi-religious populace have been often blamed on Najib's party, and the question now is, can Mahathir, the former leader, help the opposition boot the ruling government from power?
Mahathir and Anwar: From friends to foes and now, friends again
The opposition in Malaysia is weaker now compared with the last election in 2013, when the Barisan Nasional coalition led by Najib limped to the finish line, losing the popular vote and failing to snag a two-thirds majority in parliament.
Embroiled in internal squabbles and sullied by scandals of their own, the opposition for the longest time could not even agree on who would lead the country should they win the elections.
Cue the strange alliance between Mahathir and Anwar, who is back behind bars after being found guilty of sodomy a second time in 2015.
The opposition convention on Sunday declared that while Mahathir would be their candidate for prime minister at the next elections, Anwar would assume the position if they manage to upset Barisan Nasional at the polls and Anwar is able to obtain a royal pardon for his sodomy conviction, which disqualifies him from contesting the elections or holding office.
Anwar's wife, Wan Azizah Wan Ismail, is the candidate for the deputy prime minister role.
In his interview with CNN, Mahathir praised Anwar, a man he'd once mentored and then maligned, fired and incarcerated.
Mahathir said they are putting aside a bitter rivalry to focus on defeating Najib and United Malays National Organisation (UMNO), the Najib-helmed party that forms the largest constituent in the Barisan Nasional coalition.
"It is to get rid of this government. He [Anwar] wants to get rid of Najib and I want to get rid of Najib," Mahathir told CNN. "If you want to get rid of Najib we have to work together. We have to forget the past."
"I am 92 going on 93," Mahathir pointed out. "I won't last long and I am prepared for that. But for as long as I can contribute, I will continue, and I will back Anwar if that is the wish of the party."
Can Mahathir bring in the votes?
Analysts are split over whether Mahathir has the x-factor needed to oust Barisan Nasional, which has ruled uninterrupted since the country's independence in 1957.
Wan Saiful Wan Jan, chief executive of the Institute for Democracy and Economic Affairs in Kuala Lumpur, said Mahathir clearly has influence, judging by how quickly the opposition accepted him.
Mahathir "has the capabilities to bring in and influence people ... just like Anwar," Wan Saiful said. "He is very attractive among the rural voters who feel Pakatan Harapan (the opposition pact) has not been defending the rights of the Malays," he said, referring to the country's majority race, which forms the bulk of the electorate.
Wan Saiful added that support for the opposition is growing, especially in states where Barisan Nasional rules.
"Regardless what you think of the opposition, people want democracy to flourish. There are those who may disagree with Mahathir returning to active politics, but for the sake of democracy they feel UMNO must lose," he says.
However, Jayum Jawan, a professor of government and politics from Universiti Putra Malaysia, feels differently and said Mahathir's shelf life as a politician has ended.
"He will have no impact on the election. The opposition has not been able to penetrate rural areas as the people there seem comfortable with what the government has done for them. Rural voters want stability," he says.
'He has done a lot of damage'
While opposition leaders have welcomed Mahathir, some rank and file politicians remain skeptical.
S. Manikumar, an opposition politician, said many party members are reluctant to back Mahathir openly because policies drafted during his reign favor the Malay majority at the expense of ethnic Chinese and Indian nationals.
"He has done a lot of damage in the past 30 years. He has no doubt developed the nation but many still view him as a racist," Manikumar said. "The Indians, for one, were marginalized during his tenure as policies were not in their favor. As far as the lower and middle-class Indians are concerned, their votes may sway to Najib."
Other opposition politicians, such as Othman Karim, said while those in the party may have their differences with Mahathir, "an enemy of an enemy is a friend."
Yet others believe that Mahathir's alliance with the opposition and his willingness to admit to past mistakes means he will atone for previous political blunders.
Charles Santiago, an opposition Member of Parliament, said the opposition needs a strong personality like Mahathir to lead its mission.
"Many say the country is headed in the wrong direction and we need someone strong from the Malay community to counter Najib," he said.
"Dr Mahathir is our top dog right now. Politics is a very strange thing. One minute you are enemies, the next minute you are friends."