DAVAO - The war of words between presidential aspirants Davao City Mayor Rodrigo Duterte and former Interior Secretary Mar Roxas rages on.

Over the weekend, the Liberal Party (LP) standard bearer taunted Duterte for supposedly backing out from his challenge of settling their feud through a debate, fistfight or a slapping match.

"Hamon sa sampalan, umurong; hamon sa suntukan, umurong; hamon sa debate, umurong. Ang lider ng ating bansa hindi umuurong sa hamon, hinaharap ito," Roxas said.

Duterte lashed back at Roxas by saying that he is a "global leader," unlike the administration candidate who, he said, is merely a "Cubao leader."

"I am a global leader. Si Mar, Cubao leader lang yan," he said. "Si Mar, sige hamon ng debate, Christmas time ngayon."

Duterte also remained unfazed even as another petitioner questioned before the Commission on Elections (Comelec) the validity of his substitution for erstwhile PDP-Laban standard bearer Martin Diño.

Rizalito David on Monday asked the poll body to declare as null and void Duterte's substitution for Diño and order the cancellation of the mayor's certificate of candidacy (COC) ''for not having validly and seasonably filed."

READ: David asks Comelec to exclude Duterte from race

"Kawawa naman ako. Sige lang, okay lang sa akin. No problem," said Duterte.

"Magkita na lang kami sa Malacañang. Imbitahan ko sila meryenda, ang paborito ko yung maruya," he quipped.

DONAIRE SUPPORTS DUTERTE

Duterte, meanwhile, welcomed the support of "The Filipino Flash" Nonito Donaire.

"At least may boxer ako na isa na sa akin, ang isa kasi ayaw sa akin. Ito, champion man din," Duterte said.

The Davao City mayor was referring to senatorial aspirant Sarangani Rep. Manny Pacquiao, who has said he will not leave the team of opposition candidate Vice President Jejomar Binay despite being considered by Duterte to be included in his slate.

READ: Pacquiao not abandoning Binay

Duterte, however, stressed that he and Pacquiao remain friends and that he will still support the boxing champion's candidacy for the Senate next year.

RISE IN PRE-ELECTION SURVEYS

The camp of Duterte also welcomed his rise in pre-election surveys.

In the latest Pulse Asia poll, conducted December 4 to 11, the mayor landed in second place with 23 percent of the respondents saying they would vote for him if the elections were held at the time the survey was conducted.

Binay topped the survey with 33 percent support from voters. Duterte was followed by Senator Grace Poe, who garnered 21 percent voter support, and Roxas with 17 percent.

READ: Binay regains lead, Poe suffers dip in 2016 race: Pulse Asia

"That the timing of the survey coincided with the misunderstanding on the Traffic-Pope issue has hindered an even more preference for the mayor, who was already dismissed by many as out of the race.

Yet, his ratings for Mindanao would show him as the only one with a clear bailiwick. And his growing support among those in the ABC class, who abhor cussing, is the highest among the 5 presidential bets," said Peter Tiu Lavina, head of media relations.

"Consider too that while the others have been preparing as early as 2010, Duterte was a late comer and has not spent in ads unlike the others," Lavina added. -- Report from Hernel Tocmo, ABS-CBN News Southern Mindanao