MANILA - Senator Antonio Trillanes IV on Monday continued his word war against Sen. Richard Gordon even as the latter confirmed he will file an ethics complaint against the former soldier.

In an interview on DZMM, Trillanes said Gordon "caved in to pressure" when he eventually decided to grant the motion to summon President Duterte's son, Davao City Vice Mayor Paolo Duterte, and son-in-law, Mans Carpio, husband of Davao City Mayor Sara Duterte, to the next Senate hearing on September 7.

Both Duterte and Carpio have agreed to attend the hearing.

• Duterte son, in-law vow to attend Senate probe

Last week, Trillanes criticized Gordon, who is the chairman of the Senate Blue Ribbon Committee, for badgering resource persons in the Senate inquiry on Customs corruption while failing to act swiftly on his motion to summon Paolo Duterte and Carpio to the next hearing.

"'Yun yung sinasabi ko sa kanila. Let these people defend themselves. Nakakahiya na yung senador pa yung parang first line of defense sa kanila...Kay tapang-tapang mo dun sa mga ordinaryong mga resource person, binoboljak mo. Tapos eto pinapatawag lang parang nangangatog ka," he told radio DZMM.

"He missed the opportunity to show his independence...Naghintay pa ng senyales," he added.

For his part, Gordon said he is determined to file an ethics complaint against Trillanes for showing disrespect to fellow senators. Last week, he criticized Trillanes for calling the Senate Blue Ribbon committee a "komite de abswelto" and making various accusations.

• Gordon cites Trillanes in contempt, threatens to file ethics case

"It’s gonna be filed today. I don’t need signatories. I have the support of more than 10, more than 12, more than 14 senators," he told reporters.

Senate Majority Leader Tito Sotto said members of the ethics committee met on Monday to discuss the complaint.

"What was discussed during the caucus was confidential. But I would just say that Senator Gordon’s figure was accurate," he said.

Senate President Koko Pimentel, meanwhile, said the ethics complaint will be processed normally following last Thursday's scene at the Senate Blue Ribbon committee hearing.

"Hihintayin natin yung investigation ng committee at tsaka recommendation ng committee. Basta it will be processed normally just like any other complaint," he said.

Trillanes said he will face the ethics complaint and that he did not engage in unparliamentary or unethical behavior.

"Hindi ko naman siya minura. Hindi ko naman siya sinampal...I did not use offensive language," he said.

He also defended his tag of 'komite de abswelto" during the hearing, calling it an "observation" done while the hearing was suspended.

"Pag hindi mo yan sinabi during session, hindi yan counted. Suspended yung hearing, it doesn't count," he said.