ZAMBOANGA CITY (UPDATED) -- President Rodrigo Duterte on Sunday said the opposition's senatorial candidates are heading "straight to hell," during a campaign sortie here of Senate bets backed by his party PDP-Laban.

"Otso diretso papuntang impyerno. Walang ginawa, puro criticize," Duterte said in a speech.

(Otso are going straight to hell. They do nothing except criticize.)

The President went on to attack Otso Diretso candidates one by one, including questioning the track record of his 2016 presidential election rival Mar Roxas, who has held posts in the legislative and executive branches of government.

"Ano na ang nagawa niya na naiwan sa bayan?" Duterte asked.

(What has he done that left a lasting mark in the country?)

He also tagged Sen. Bam Aquino and the reelectionist's cousin, former President Benigno Aquino III, as "unruly."

"Si Bam Aquino? What have you done really impressive? Puro kayo pasaway -- pinsan mo naging presidente," he said.

(Bam Aquino? What have you done really impressive? You are all unruly, your cousin was a president.)

Duterte also ridiculed Magdalo Rep. Gary Alejano, a former soldier who was among the leaders of botched coup attempts against former President Gloria Macapagal-Arroyo.

"Itong Magdalo, nag-revolt sa Makati. Pagdating ng pulis, nag-surrender," he said.

(This Magdalo rebelled in Makati. When the police came, they surrendered.)

The President also lambasted human rights lawyer Chel Diokno, saying his accomplishments pale in comparison to his father, former Senator Jose W. Diokno, a critic of former President Ferdinand Marcos.

"Malayo sa tatay niya," he said of the younger Diokno.

Duterte did not criticize opposition candidate Samira Gutoc because the latter "is a woman."

"Si Samira, babae 'yan. Ayoko magsalita. Ganoon ang rule, I have nothing to say to you," he said.

(Samira is a woman. I don't want to talk. That's the rule. I have nothing to say to you.)

Lawyers Erin Tañada and Romulo Macalintal, and former Solicitor General Florin Hilbay are also part of the opposition slate.

OPPOSITION BETS HIT BACK

In response to the president's tirade, Hilbay said it is the job of the opposition to point out the wrongdoings of the administration.

"Demokrasya pa rin naman tayo, at hindi diktadurya, 'di ho ba? Wala pong personalan, trabaho lang," Hilbay said in a statement.

(We are a democracy and not a dictatorship, right? Nothing personal, we're just doing our jobs.)

Diokno and Tañada also reminded the president that it is the opposition's duty to question, criticize and give alternative solutions.

For his part, Alejano told Duterte to not belittle the sacrifices of the Magdalo when they rebelled against Arroyo due to alleged corruption during her administration.

"Ang aming pag-aklas ay dahil sa talamak na kurapsyon sa gobyerno at kakulangan ng suporta sa mga tropa sa frontlines. Sila ang napapahamak habang ang ilang mga opisyal ng gobyerno ay nagpapakasasa sa nakaw na pera ng bayan," Alejano said in a statement.

(Our revolt was because of the widespread corruption in the government and the lack of support from troops in the frontlines. They were the ones in danger while some government officials enjoyed money stolen from the people.)

Alejano added that his criticism against the administration "offer[s] solutions and alternatives to policies which are detrimental to the country and the Filipinos."

Gutoc thanked the president for showing respect but asked him to "afford the same respect to all women."

Gutoc also appealed to Duterte to stop a "bloodier" drug war.

Malacañang earlier said there was nothing wrong with Duterte endorsing administration allies who are running in the elections, even as it denied that the chief executive has turned his public functions into a virtual campaign trail.

• Palace denies Duterte events being turned into campaign rallies

The Commission on Elections, meanwhile, earlier said negative campaigning "has always been allowed." -- Report from Leizle Lacastesantos, ABS-CBN News

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