Philippines' Pacquiao says he is not to be counted out of presidential race

Shrugging off his low rating in opinion polls, Philippine politician and former boxing star Manny Pacquiao says his impoverished roots make him the best person to be president, as he warned voters to avoid corruption-tainted candidates.

Pacquiao questioned why people supported Ferdinand Marcos Jr, the current frontrunner for the May 9 vote, pointing to the plundering of the country's wealth during the harsh authoritarian rule of his late father and namesake.

"The root cause of our country's problem is corruption and then we would vote for a candidate who has been tainted by corruption? What happened to us as a nation? Where is our intelligence?" Pacquiao said in an interview with Reuters late on Thursday.

Pacquiao is trailing in fourth place on 6 per cent in the latest opinion poll, well behind Marcos, who is leading with 56 per cent.

The incumbent senator has made fighting corruption a centrepiece of his campaign, vowing to strengthen efforts to recover billions of dollars missing since the fall of the Marcos dictatorship in 1986, as part his anti-graft platform.

Marcos's family was accused of plundering an estimated $10 billion during his late father's two-decade rule, spending it on jewellery, real estate and artworks including those of Pablo Picasso and Claude Monet.

"Why are we in poverty? Because we don't have money? Wrong. Because of corruption," Pacquiao said at his campaign headquarters.

Marcos's camp did not immediately respond to a request for comment, but the candidate has previously said he cannot apologise for what his father did.

Pacquiao has also sparred with incumbent President Rodrigo Duterte over territorial disputes in the South China Sea. He said he would not be bullied by China if he won the presidency.

"I dare you, bother the Filipino fishermen and I'm the one you would have to face," Pacquiao said in comments addressed at China. "To be bullied is not in my vocabulary."

China reiterates its claims of sovereignty in the disputed waterway whenever Manila complains about its actions towards Filipino fishermen.

Duterte has faced criticism for not confronting China more over the conduct of its military, coast guard and fishing fleet in waters around the archipelago, arguing it was pointless since Manila was no match for Beijing's military might.

If need be, Pacquiao vowed to deploy navy ships in the disputed waters to protect his country's fishermen and said he valued his country's relationship with the United States, which he called as "our best friend."

The only man to hold boxing world titles in eight different divisions, Pacquiao retired from boxing in September after the sport brought him huge riches to propel him from humble beginnings as a dirt-poor youngster doing odd jobs to survive. 

Pacquiao said he was unfazed by his low rating in polls, convinced the poor would deliver the votes for him on election day.

His impoverished beginnings made him the best person to take on the presidency, because he understood what it was like to be poor, he said.

"If we are going to discuss poverty, that is not a concept for Manny Pacquiao. I felt and lived that and that is why I want to lift the people out of poverty," he said.