At the twilight of his political career, former Prime Minister Mahathir Mohamad is aiming to make a comeback at age 92 by trying to demolish the party that helped him transform Malaysia into one of Southeast Asia’s most-prosperous nations.

During his 22-year-rule that began in 1981 – the longest in Malaysia’s history – Mahathir delivered prosperity with solid backing from the United Malays National Organization, or UMNO, the anchor party in a ruling bloc that has dominated Malaysian politics since independence from Britain in 1957.

But Mahathir, a former medical doctor popularly known as “Dr M,” quit UMNO and came out of political retirement two years ago, in protest over allegations of financial malfeasance directed against Prime Minister Najib Razak, his former protégé.

He said UMNO needed to be vanquished.

“It is not easy for me to destroy the party that I loved for 60 years,” Mahathir said, referring to UMNO. “But now, today, I am fighting to take it down.”

Mahathir stunned the nation when he bolted to the opposition and joined forces with his arch nemesis, former Deputy Prime Minister Anwar Ibrahim, whom he once sent to jail on a sodomy charge.

Mahathir is leading Pakatan Harapan (PH), an amalgam that includes the Malay-led multiracial People’s Justice Party (PKR), the Democratic Action Party (DAP), the Malaysian United Indigenous Party (Bersatu) and the faith-based National Trust Party (Amanah). All are campaigning under PKR’s banner after authorities recently rejected Pakatan’s application for registration as a political coalition and also de-listed Bersatu as a party.

Mahathir, during an interview with BenarNews in September 2016, described UMNO as “beyond resuscitation, beyond turning around.”

“It has become very bad. It has become very, obviously, very corrupt. The leaders are corrupt. They don’t express the views of the people,” he said. “So we have no choice but to form another party.”

‘Obsessed about control’

Najib, who is pitching a campaign promise of economic growth built around infrastructure projects, explained his falling out with Mahathir during an interview with Bloomberg News last week.

“I think he’s obsessed about control, about calling the shots, in fact, when we were quite close together he even suggested establishing a council of elders,’’ Najib said. “Of course, you can imagine who’s going to chair the council of elders. And a sitting prime minister, after every cabinet, I suppose I would have to march to his office to get his consent.”

In recent years, Mahathir has been drawn back into the political spotlight because of his multiple jabs at Najib, his former political student who has been embroiled in a multibillion dollar financial scandal involving 1MDB, a state development fund.

Mahathir, and other opposition leaders and activists, have also accused Najib of redrawing electoral boundaries within weeks of the polls to favor UMNO’s candidates. But Najib told Bloomberg News that Mahathir had also presided over several district redraws when his former political mentor was in power.

Critics also accused Najib of further stifling dissent or criticism against his government after the country began prohibiting “fake news” in April. Parliament passed a law then to make the “malicious” spread or creation of fake news punishable by up to six years in prison and a maximum fine of up to 500,000 ringgit (about U.S. $128,000).

On Wednesday, authorities said they were investigating Mahathir under the new law over claims last week that he suspected sabotage of a private plane that was supposed to take him from the capital Kuala Lumpur to Langkawi district, where he is running for a parliamentary seat.

“We have opened an inquiry based on a police report made against Mahathir,” Kuala Lumpur police chief Mazlan Lazim told reporters.

Private medical practice

Mahathir will turn 93 on July 10. He was appointed as the country’s fourth prime minister on July 16, 1981, but he began his political career in 1946 when he joined UMNO.

Mahathir, the son of a school principal, was educated at Sultan Abdul Hamid College, one of Malaysia’s oldest and most prestigious schools, based in his home state of Kedah.

After receiving his degree in medicine from the University of Malaya, Mahathir worked as a government health officer and later ran a private medical practice in Kedah for seven years. He was elected to parliament in 1964.

In the 1940s and 1950s, using the pen name “Che Det,” Mahathir wrote articles on Malay politics and economic issues for The Sunday Times.

On Sept. 26, 1969, Mahathir was sacked from UMNO by the country’s first premier, Tunku Abdul Rahman, who was reportedly irked by Mahathir’s dissenting opinion about ethnic Malay nationalism. He rejoined the party after Tunku Abdul’s resignation in September 1970.

Malaysia’s economy under Mahathir’s leadership boomed from 1991 to 1995, with annual gross domestic product (GDP) growing an average 8.7 percent and low unemployment rate of about 2.5 percent. According to the World Bank, the Muslim-majority nation that is now known for its semiconductor factories posted an estimated 2017 GDP of U.S. $989 billion, making it the third wealthiest nation in Southeast Asia, after Singapore and Brunei.

Authoritarian tendencies

During Mahathir’s early tenure as prime minister, he solidified his authority by dramatically reducing the power of the sultans who ruled Malaysia’s states.

He was also accused of having authoritarian tendencies after he ordered the arrests and detention of more than 100 people, including opposition leaders and activists, under the internal security act in 1987.

In 2017, Mahathir stopped short of apologizing, but accepted blame for the arrests.

“I accept the blame even though the detention was not my decision,” he said in a blog post, decades after the operation, dubbed Ops Lalang.

“I am now told that detainees were tortured. I regret that the detainees in Ops Lalang were tortured. This is against the law,” he said.

Longtime parliamentarian Lim Kit Siang, leader of the Democratic Action Party, and his son, current DAP secretary-general Lim Guan Eng, were among those rounded up in the crackdown described as an effort to prevent race riots. Lim spent 17 months in detention while his son was jailed for 12 months.

Three newspapers – The Star, Sin Chew Daily and the now-defunct Watan – were also suspended.

Yet Malaysia’s high-tech industry, including software engineering, grew under Mahathir, as the nation also saw the building of mega projects, including the Petronas Twin Towers – the world’s tallest buildings until 2004.

At the peak of his leadership, Mahathir developed and made Putrajaya the country’s new administrative center in 1999, replacing the old city Kuala Lumpur.

Malaysia emerged relatively unscathed from the Asian financial crisis in the 1990s after Mahathir defied the International Monetary Fund by introducing controversial currency controls that effectively isolated his country from the global economy.

Admitting wrong decision

During an interview with Sin Chew Daily at his office in Putrajaya in March, Mahathir said he would not have sacked Anwar, if he could have turned back the clock and chosen again.

Mahathir said he made a wrong decision to go strictly by the book in acting against Anwar in 1998.

“From a political point of view, I would not have done this. When I was the prime minister, I promised myself not to do anything that would make people hate me,” Mahathir said.

On Feb. 29, 2016, Mahathir left UMNO after a public outcry over allegations that Najib had allegedly helped embezzle funds from 1MDB.

U.S. authorities allege that between 2009 and 2014, top executives of 1MDB and Najib’s associates looted at least $4.5 billion from the fund in a complex money-laundering scheme through acquisition of properties and bank deposits in the United States, Singapore, Switzerland and other countries.

According to court documents filed by the U.S. Justice Department in a civil case that seeks to recover some of that money, about U.S. $681 million landed in Najib’s private bank accounts. Najib said the cash was a political donation from Saudi Arabia’s royal family. He denied any wrongdoings related to1MDB.

“I left UMNO for a reason,” Mahathir told reporters. “That it is now a party that protects Najib at all costs, from any wrongdoings committed by him.”