By Lindsay Murdoch in Bangkok Profane Filipino frontrunner lashes Australian policy again Rodrigo Duterte continues to widen his lead.
He vowed to pardon himself for murder, joked about his penis, said he would kill his own children if he caught them with drugs and took a new swipe at Australia over its policy on the South China Sea. 
Rodrigo Duterte continues to widen his lead in a profanity-laced campaign to become president of the Philippines at elections on   May 9. If the polls are correct, Australia's traditionally strong defence and diplomatic relationship with the Philippines could be barrelling towards a cliff.
Pollsters are also predicting that Mr Duterte's deputy could be Ferdinand Marcos jnr, son of the late dictator, who was forced to flee Manila in 1986. Turning up in a sports shirt and corduroy jeans at a business forum in Manila, Mr Duterte, 71, criticised Australia over its policy to remain neutral in the Philippines' bitter row with China over the disputed waters of the South China Sea.
"Why the hell didn't Australia, the Americans or even Japan stop it?" he said.
Mr Duterte did not mention that earlier in   April Australian forces had taken part in war games with Philippine and US forces in those waters, angering China. Nor did he mention that China's aggressive pursuit of its claim to almost all of the South China Sea has in recent years drawn Canberra closer to Manila.
Mr Duterte also repeated an earlier warning that he would be prepared to sever diplomatic ties because Australia's ambassador in Manila spoke out against a joke he made about raping an Australian missionary, whose throat was cut in a jail after she was raped by prisoners in 1989.
Mr Duterte made his name as the mayor of Davao in Mindanao, the violence-wracked southern island where human rights groups accuse him of operating murder squads.
At the business forum he defended his history of womanising.
"I was separated from my wife. I'm not impotent. What am I supposed to do? Let this hang forever?" Mr Duterte asked, referring to his penis. "When I take Viagra, it stands up."
The key focus of Mr Duterte's campaigning has been pledges to wipe out crime nationwide within six months, declaring his presidency would be "bloody" and vowing to pardon soldiers and police charged with human rights abuses.
The promises appear to be resonating with millions of people in a country where crime has risen fivefold in recent years. "You rape a child in my city? I will kill you," Mr Duterte said last year. "I have no problem with that."
Mr Duterte told the business forum he wanted to prioritise education, complete infrastructure projects and find a solution to Manila's traffic jams, before refusing to answer questions and rushing to a campaign rally.
His nearest rival is 47-year-old senator and mother of three Grace Poe, the adopted daughter of late movie star Fernando Poe, who made an unsuccessful bid for the presidency in 2004.