MANILA - The front-runner to be the next president of the Philippines, tough-talking city mayor Rodrigo Duterte, widened his lead in the last opinion poll before Monday's election.

The poll conducted from May 1 to May 3 and published late on Thursday put Duterte's support at 33%, the same as a week earlier, with his main rival, Grace Poe, a senator who was once favorite to win, down 2 points to 22%.

The BusinessWorld-Social Weather Stations (SWS) pre-election survey, which questioned 4,500 voters, put former Interior Secretary Manuel Roxas, President Benigno Aquino's hand-picked successor, third with 20% and Vice President Jejomar Binay fourth with 13%. Senator Miriam Defensor Santiago is trailing the presidential race with 2%.

Brash and scathing of the political establishment, the rise of the former prosecutor and mayor of the southern city of Davao has dismayed business chiefs, investors and diplomats who see him as a clown with no clear economic policies.

Allegations made last week by a senator running for vice-president that Duterte, 71, had undeclared millions of pesos in a bank were dismissed by the front-runner as a "publicity stunt" and have not dented his popularity with voters who like his blunt style and tough-on-crime approach.

"The vote for Duterte is a protest vote, not really a Duterte vote," Ramon Casiple of the Institute for Political and Electoral Reforms told newspaper BusinessWorld where the results of the survey were first published.

"People are showing that they are really frustrated and angry with the current administration. If nothing changes, Duterte will win; he got the imagination of the public."

Duterte received another boost on Thursday when he won the endorsement of a major Christian sect which is widely considered as a bloc vote of 1.2 million people.

Meanwhile, Senator Bongbong Marcos and Representative Leni Robredo led the pack of vice-presidential aspirants with 29% and 28%, respectively.

Marcos gained 4 points from the preceding survey while Robredo recorded a 2-point increase.

Early front-runner Senator Chiz Escudero remains in third place with 15%, down 3 points from the preceding survey. Senator Alan Cayetano, Duterte's running mate, is at fourth place with 13%. Senators Antonio Trillanes IV and Gringo Honasan are trailing the race with 3% each.

CONSISTENT FRONT-RUNNER

In the ABS-CBN survey conducted by Pulse Asia, Duterte kept his 33-percent rating for a second week in a row.

Roxas and Poe were in a statistical tie for second place with 22 percent and 21 percent, respectively. Binay polled 17 percent, while Santiago got 2 percent.

Duterte also retained his lead against other presidential candidates in the final Laylo 2016 pre-election survey conducted for The Standard.

The Davao City mayor got 32.43%, while Poe and Roxas were in a statistical tie in second place with 24.58% and 21.67%, respectively. Binay is in fourth place with 15.44%, followed by Santiago with 2.37%.

About 54 million of a population of 100 million are eligible to vote on Monday's elections. - with a report from Reuters