MANILA (2nd UPDATE) - One against 8.

Hugpong ng Pagbabago chair and Davao City Mayor Sara Duterte-Carpio dared on Friday the candidates of opposition slate Otso Diretso to face her in a debate.

"Kami na lang, Inday Sara versus 8," Duterte-Carpio said.

The daughter of President Rodrigo Duterte made the remark after the Commission on Elections rejected the opposition slate's request for an official debate for senatorial candidates running in the May 13 midterm polls.

• Comelec junks Otso Diretso debate request

Sought for comment on the Comelec's decision, Duterte-Carpio said: "Nothing. It is not our petition."

Otso Diretso bets earlier filed a petition asking the poll body to craft rules and facilitate public debates.

It had also been urging candidates endorsed by the Duterte administration to engage in a public debate and explain their stance on key issues and national policies.

All Otso Diretso candidates-- Gary Alejano, Sen. Bam Aquino, Chel Diokno, Samira Gutoc, Pilo Hilbay, Romy Macalintal, Mar Roxas, and Erin Tañada--have joined televised debates for the May 13 polls.

Duterte-Carpio had previously criticized the opposition slate's "fixation" on debates.

"Kung ang mga HNP-supported senators ay ang sun, ang HNP ay ang moon, sila po ay parang black hole. Very depressing, dark and very disorganized," she said.

(If HNP-supported senators were the sun and the HNP were the moon, they (opposition candidates) are like a black hole. Very depressing, dark and very disorganized.)

• Sara Duterte on opposition bets: 'Depressing black holes obsessed with debate'

Otso Diretso fires back: She’s not a senatorial candidate

Tañada, however, denied Duterte-Carpio’s dare, saying she is not even running for senator.

“Eh hanggang ngayon, hindi nga nagsasalita ang mga kandidato ni Sara na lahat po tayo ay sinungaling. Dapat nagsasalita po sila para ipaglaban ang integridad nila,” he told reporters in Digos City.

(Until now, Sara's candidates have not spoken, have not said we are all liars. They should speak up to fight for their integrity.)

Hilbay echoed Tañada, saying they will accept the debate challenge if it will be with fellow senatorial candidates.

“We’re hoping that the senatorial candidates of HNP can find courage to confront us, so that the people will be fully informed. Hindi to laban ng Otso Diretso against mayor Sara Duterte (This is not a fight of Otso Diretso against mayor Sara Duterte),” he said.

Meanwhile, Hilbay said Comelec abandoned its duty to hold a fair and free election when it denied the opposition’s request for a debate.

“Kaya tingin namin lugi ang mga mamamayan if the candidates are not allowed to participate in a debate dahil hindi nabibigyan ng opportunity yung mga tao na makilala at makilatis yung mga kandidato,” he said.

(That's why we think the masses are losing if the candidates are not allowed to participate in a debate because they are not being given opportunities to get to know the candidates.)

–With reports from Hernel Tocmo, ABS-CBN News