Philippine leader Benigno Aquino called Friday on the trailing presidential candidates to unite against frontrunner Rodrigo Duterte, in a sensational finale to one of the nation's most divisive election campaigns.
Aquino has repeatedly warned Duterte is a dictator-in-the-making, and made the plea after polling showed the favourite had kept a huge lead ahead of Monday's elections despite allegations he has overseen vigilante death squads and a spate of controversies over vulgar campaign speeches.
Aquino told CNN Philippines in an exclusive interview that he was trying to get the other four presidential candidates to unite to defeat Duterte, who he said was likely to get 30 percent of the vote.
"The whole point is to get even two of them to unite... then we have more than 40 percent," Aquino said.
In the Philippines, a president is elected simply by who gets the most votes.
Duterte has 33 percent support, with Senator Grace Poe next at 22 percent and administration pick Mar Roxas at 20 percent, according to the latest poll released on Friday by Social Weather Stations.
Aquino said he had talked to Roxas, his longtime friend and fellow Liberal Party stalwart, and sent a text message to Poe to try and get them to forge an eleventh-hour partnership.
This would mean one of the candidates withdrawing. If one did, they would ask Filipinos to instead vote for the other, but there are no guarantees the public would do so.
Roxas gave a short speech on Friday night saying he was ready for talks with Poe.
"I call for unity, I call for decency, I call for democracy," Roxas said, without saying whether he would be prepared to back out.
Poe, the adopted daughter of a dead movie star who owes her popularity to her father, said she would not pull out of the race, seemingly leaving a Roxas withdrawal the option for a unity ticket.
"We can talk anytime. But I will say this now... if they are thinking that someone among us will withdraw, I won't withdraw," Poe told reporters.
Duterte, 71, has gained support across all sectors of society by fashioning himself as an anti-establishment politician who can achieve quick fixes to deep-rooted problems, particularly crime.
The mayor of the southern city of Davao has vowed to end crime within six months of his presidency by ordering security forces to go on a killing spree.
He has said he would kill tens of thousands of criminals, then pardon himself if he was found guilty of mass murder.
Duterte has been accused of running vigilante squads in Davao that have killed more than 1,000 suspected criminals. At times he has boasted about his involvement but on other occasions denied any links to the vigilantes.
A self-confessed serial adulterer, he also generated outrage last month when he joked at a campaign rally that he had wanted to rape a "beautiful" Australian missionary who was sexually assaulted and murdered in a 1989 Philippine prison riot.
He has faced a barrage of last-minute attacks in recent days over allegations he hid millions of dollars in undisclosed bank accounts.
Duterte has also infuriated his opponents by warning he is prepared to shut down Congress if lawmakers disagree with him, and establish a revolutionary government that could rewrite the constitution.
Upending conventional political wisdom, the controversies appeared to have fuelled his popularity.
Aquino, whose mother led the 1986 "People Power" revolution that toppled dictator Ferdinand Marcos, said Thursday the Philippines was in danger of repeating history if Duterte was elected.
"We won't be able to run if we make a U-turn back to a martial-law style," Aquino said at Roxas campaign rally.
"We will go back to a Marcos-style martial law where he will monopolise the decision making."
Duterte's campaign manager on Friday described the election as a "war of the classes".
"All the innuendos, attacks, and mud thrown at us and our candidate, are acts of desperation, of panic and of cowardice," Leoncio Evasco said in a statement.