Nineteen years ago Mahathir Mohamad, while prime minister of Malaysia, denounced his freshly sacked deputy Anwar Ibrahim as “morally unfit” for leadership, following allegations of corruption and sodomy.

Now the duo – formerly known for a father-and-son-like closeness – has seemingly reunited to take down a common foe: embattled Prime Minister Najib Razak, who is facing global scrutiny following his alleged involvement in the 1Malaysia Development Berhad (1MDB) corruption scandal.

Mahathir, now 92, has criticised Malaysia’s current head of government and described him as dictatorial. Meanwhile, Anwar is still serving a prison sentence following a second sodomy charge in 2008.

Mahathir’s newly formed political party, Parti Pribumi Bersatu Malaysia (commonly referred to as “Bersatu”), has joined forces with Anwar’s PKR and smaller parties to take on Najib’s party Umno and its ruling National Front coalition, under the banner of Pakatan Harapan.

In a recent interview with The Guardian, Mahathir said he had erred in not letting Anwar succeed him, the closest thing to an apology the Malaysian public has heard.

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According to analysts, the Mahathir-Anwar partnership will serve to strike a nostalgic chord with voters, particularly those who knew no other leader but Mahathir, who led the country for 22 years. To some, Mahathir and the Umno of yore, which he led, are one and the same, despite Mahathir resigning from the party last year, for the second time. For many Malays, the party under his leadership was a symbol of prosperity and stability.

Dr Bridget Welsh, visiting professor of political science at John Cabot University in Rome, said she believes Mahathir and Anwar – as well as their respective camps and loyalists – are focused on the future. She said: “It’s an agreement, so there must be some trust and mutual respect. But more importantly they share a common interest: removing Najib.”

Recently, Najib came out defending state-owned fund 1MDB and the good it had done, such as financing haj pilgrimages, sponsoring education and building houses. He said people who were using 1MDB to bring down the government – “including a former prime minister” – were not doing the right thing. This came months after the latest 1MDB-related US Department of Justice complaint seeking to recover US$540 million in assets including a yacht, a Picasso painting gifted to Leonardo DiCaprio, and a diamond necklace bought with money stolen from the government fund.

Welsh said this defensiveness showed “a real sense of threat and anxiety” on the part of Najib’s leadership, unsurprising given Mahathir’s achievements in terms of the nation’s stature and economic performance compared to today’s weak ringgit and flagging national sentiment.

All eyes will be on the next general election. Though no date has yet been set for the poll, it will be before August 2018.

And although some believe the National Front will win decisively with the help of handouts such as the popular Bantuan Rakyat 1Malaysia – cash reliefs for poor households amounting to anywhere between US$93 and US$280 – the money may well be running out.

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“There is less money to spend, and whatever is being handed out doesn’t make a substantial dent in the additional cost of living that is a product of Najib’s governance,” Welsh said. “As such, the money is focused on buying the elites in the system, not the ordinary voters. He won’t have as much cash to splash around.”

She added: “While there will be voters supporting him, the tactic he uses for them is not money but instead fear, racism, and religious rhetoric.”

These issues are ones that Mahathir, with his liberal Islamic values, can face head-on. He is well versed in the position of Malays in Malaysia and the affirmative action afforded them, as well as the intricacies of race relations.

While the opposition largely dominates urban seats, particularly in Malaysia’s richest state Selangor, rural constituencies are more numerous. In the 2013 general election, the opposition seized 89 of 222 federal seats, seven more than in the previous polls in 2008, denying the National Front a two-thirds majority in parliament for the second time.

But with the opposition largely seen as disunited – particularly after the breakaway of the Parti Islam se-Malaysia (PAS) in 2015 – its effectiveness lies in focusing on the upcoming elections.

Ibrahim Suffian, head of independent opinion polling firm Merdeka Centre said that, to succeed, Mahathir needs to find a way to cooperate with PAS and ensure straight fights instead of three-corner tussles for seats. “If not, the Malay vote is split and [National Front] will likely be able to maintain its advantage,” he said. “The key challenge for the alliance between the erstwhile enemies is not their internal factions but rather their coalition partners DAP and Amanah to accept a compromise with other parties.”

Dr Meredith Weiss, associate political science professor with the State University of New York at Albany, echoed that.

“It’s not a one-on-one between Mahathir and Najib,” she said. “Neither coalition begins and ends with the leader, and the question of how much support Bersatu really has arises. The real question is that of seat allocations, and how to ensure PAS does not split the votes.”

Just last week, Pakatan Harapan announced its new leadership structure. Anwar will serve as de facto leader, PKR president Wan Azizah Wan Ismail will be president, and Mahathir will be chairman.

Anwar’s daughter, member of parliament Nurul Izzah, said the coalition’s goal was “simply to rescue Malaysia from the dire straits that it currently finds itself in.”

She said: “Anwar supports these goals, having spent his entire life, at great personal cost, to achieve them. Whatever their past differences have been, I believe Dr Mahathir shares this dream.”

Whether this alliance will go the distance remains to be seen, but even Teflon man Najib has cause to worry.

“He presided over one of the worst scandals in global history in terms of money laundering and corruption,” said Welsh. “Anyone in that position would have something to worry about.”