MANILA, Philippines -- Millions of Filipinos lined up Monday in blazing heat to vote for a president that opinion polls show will likely be a foul-mouthed mayor who gained huge popularity with his pledges to kill criminals and end corruption within six months.

Weary of poverty, corruption and insurgencies in the hinterlands, voters are looking for a radical change at the top, and hope the man to lead it is Rodrigo Duterte, the 71-year-old mayor of the southern Davao city.

An ex-prosecutor, Duterte has peppered his campaign speeches with boasts about his Viagra-fueled sexual prowess and jokes about rape. But Duterte has successfully tapped into discontent and voters appear willing to overlook his foul language.

"All of you who are into drugs, you sons of bitches, I will really kill you," Duterte told a huge cheering crowd Saturday in his final campaign rally in Manila. "I have no patience, I have no middle ground, either you kill me or I will kill you idiots."

Philippine presidential candidate and Davao city mayor Rodrigo Duterte kisses the Philippine flag during a political campaign rally before the national elections at Rizal park in Manila, Philippines, May 7, 2016.

REUTERS

The brash Duterte, who has been compared to U.S. Republican presumptive nominee Donald Trump, has threatened to close down Congress and form a revolutionary government if legislators stonewall his government.

This has alarmed the political establishment, which fears that Duterte will squander the hard-won economic progress under outgoing President Benigno Aquino III. Aquino has called Duterte a threat to democracy, and likened him to Adolf Hitler.

Besides Duterte, former Interior Secretary Mar Roxas, backed by Aquino, and three other candidates are vying to lead one of Asia's liveliest democracies. More than 45,000 candidates are contesting 18,000 national, congressional and local positions in elections that have traditionally been tainted by violence and accusations of cheating, especially in far-flung rural areas. The results are not expected for at least 24 hours, perhaps longer.