Manny Pacquiao and President Duterte, once political buddies, are suddenly throwing punches at each other. What happened?

• President Duterte tore into political ally and boxer Manny Pacquiao, calling him s--- on Thursday.
• The two have been exchanging words recently, which some see as the breakdown of a once strong political friendship.
• Experts say the squabble could be a political ploy or simply posturing over next year's presidential elections.

Philippine President Rodrigo Duterte ripped into political ally Sen. Manny Pacquiao on Thursday, saying that the boxer-turned-senator was "blubbering in his mouth" in his earlier comments about corruption in the national government.

Duterte also lambasted Sen. Pacquiao's decision to fight Errol Spence Jr. in August.

"I would expect him to sit in Congress. Do not go anywhere. Finish and find out the corruption that you are talking about. If you're only going to report for a month or two, then I would say that you are a s---. A s--- is a s---," said Duterte of the eight-division boxing champion.

Duterte's incensed comments, made at a media briefing, are just the latest in a series of tirades aimed at Pacquiao, who has recently leveled criticism at the president's administration as well. Their months-long exchange is seen as the breakdown of a once strong political and personal friendship, and experts say this is likely to do with next year's looming presidential election.

How the Pacquiao - Duterte relationship began

Sen. Manny Pacquiao first ran for Congress in 2007, failing initially, but later winning a seat for the Sarangi province in 2010. He then ran for a senatorship and won in 2016 as the seventh of 12 new members of the Philippine senate.

Meanwhile, Rodrigo Duterte ran the city of Davao from 2010 to 2016, swapping between the positions of Mayor and Vice-Mayor with his daughter Sara Duterte-Carpio as running mate.

When Duterte declared his run for the presidency in 2016, he asked Filipinos to support Pacquiao's senatorial run, even though the boxer had already aligned with Duterte's political rival, Jejomar Binay.

"Even if he is not on my side, kindly support Pacman. He is my friend. We are both from Mindanao," he said, referring to an island where he and Pacquiao both lived during their childhoods.

Duterte even put Pacquiao on his "dream team" of senators, calling him one of the "sure winners."

Pacquiao said that he had always been on Duterte's side but stuck with Binay because he already declared for him while Duterte mulled over his own candidacy.

During Duterte's presidency, Pacquiao also staunchly supported the former's controversial war on drugs. And in 2020, Pacquiao was elected the party president of Duterte's left-leaning PDP-Laban political party.

Some pundits also saw Pacquiao as one of Duterte's potential successors when the incumbent president's six-year term ends in 2022, according to the Philippine Constitution.

Pacquiao vocally critical of Duterte

But earlier this year, Pacquiao started taking jabs at Duterte's administration.

He criticized the president's friendly relationship with China, saying that Duterte was too soft over territorial disputes in the South China Sea.

"I find it lacking compared to how he was before he ran for President. He should have continued that so that we get some respect," said Pacquiao.

The president responded in June by saying that Pacquiao should "study first" before giving his thoughts.

Tensions flared even further when Pacquiao spoke of corruption in Duterte's government, particularly in the Department of Health and its pandemic spending.

"I think declaring war against corruption is bigger than illegal drugs," Pacquiao told local media site News5 in an interview on June 22, referring to Duterte's emphasis on the war on drugs.

Duterte hit back by challenging Pacquiao to name the corrupt officials in his administration, to which the senator accepted on June 29. But Pacquiao also told reporters that he was not trying to attack the president.

"I only wanted to help in his campaign to curb corruption," he told reporters at a US Independence Day celebration.

Duterte snapped back at Pacquiao anyway. "When you are a champion in boxing, doesn't mean to say you are a champion in politics," he said.

Experts weigh in

Some believe the fight is nothing more than a ploy by Duterte's administration to install an opposition led by Pacquiao.

"This ploy would somehow downplay a possible upswelling of the existing opposition allied to the late President Noynoy Aquino," Eric Batalla, a professor of political science at De La Salle University in Manila, told Insider. Aquino died last week and was commemorated with tributes across the country.

But even if it is a ploy, it could still be doing real damage to the pair's relationship.

"At the same time, it is highly likely that Pacquiao's corruption criticism also hurt the feelings of the president. Duterte appears to be extra sensitive to such allegations coming from government officials, allies, and critics alike," Batalla told Insider.

Pacquiao could also be positioning himself for a run for president, putting him in the way of Duterte's "anointed successor," he added.

Professor Ador Torneo, Director of the La Salle Institute of Governance, said it is likely that Pacquiao will run for president with or without Duterte's support.

"It is likely that his criticism of corruption in the government, along with securing the presidency of the PDP-Laban party, is already part of a deliberate move to establish himself as a candidate distinct from the administration," he said.