A wide swing in voter preference put Philippine Vice President Jejomar Binay at the top of a presidential election survey and pushed former front-runner Senator Grace Poe to third place as she battled moves to disqualify her from the race. The survey puts the new No. 2 as Davao city mayor, Rodrigo Duterte, who draws votes from the south, where he is from, and from Filipinos attracted by his anti-establishment style.

Binay's support surged to 33 percent in a Dec. 4-11 survey by Pulse Asia, released Tuesday, from 24 percent in October. Meanwhile, Poe slumped to 21 percent from 39 percent.

The polling period coincides with Poe's disqualification by the Commission on Elections in separate cases on Dec. 1 and Dec. 11 on citizenship and residency questions. Poe's citizenship is in question because she was adopted and her biological parents are unknown. She studied and then settled in the U.S. from 1989 to 2005, and was a U.S. citizen from 2001 to 2006. She can appeal the disqualification to the full commission and then the Supreme Court.

Poe's slump in the Pulse poll mirrors her decline in a survey by Laylo Research released Monday, which showed her support falling to 28 percent this month from at least 41 percent in October.

However, Binay's surge in the Pulse survey isn't corroborated by the Laylo survey, where the vice president was still at 23 percent.

Still, it won't be the first time Binay has come from behind. When he ran for vice president in 2010 — the president and vice president are voted for separately in the Philippines — polls mostly showed him lagging but he won, beating Manuel Roxas.

Roxas is again running against Binay — he is President Benigno Aquino's candidate, but the Pulse survey shows his position and popularity slipping. He is now No. 4 with 17 percent instead of 21. Edging him out for third place is Duterte, with 23 percent support. The election will be held in May and Aquino is barred from re-election.

Binay had been leading polls since last year, even as corruption allegations against him and his family, and congressional hearings on those allegations chipped away at his popularity. He lost the lead to Poe middle of this year after she decided to run for president instead of vice president.

Binay and his family have run Makati, the Philippines' richest city, since 1986 and one of his campaign lines — roughly translated as, "This is how we live in Makati" — is he can deliver the kind of services Makati has to the rest of the country. Over almost 30 years, Binay has built a political network, in part, by sharing Makati's wealth with poorer local governments around the country via new and hand-me-down equipment and even disaster assistance.

However, critics claim he has milked Makati through bribes and by rigging and over-pricing contracts, leading to the country's anti-money laundering council to obtain a freeze on his bank accounts. They say if Binay wins, he will reverse gains Aquino claims to have made in fighting corruption, attracting investment and boosting growth.

Binay, who denies the corruption allegations, rose from poverty to become a human rights lawyer during the dictatorship of Ferdinand Marcos. When Corazon Aquino, the current president's mother, ousted Marcos in 1986, she named Binay the Makati mayor. He, his wife and his son have won every election for mayor since. He has tried to turn the attacks to his favor by associating himself with the country's poor majority in a way that some analysts liken to class war tactics.

Binay says he has the experience to run the country, in contrast with Roxas, who has a reputation for failing to execute, and Poe, who only entered politics in 2010.