While some senators urged the leadership to protect the chamber's independence, Sotto said the Senate has nothing to do with the spat. (READ: Duterte: It's my duty to name De Lima)
"Doing that will prove the allegations that the Senate is really an 'old boys' club' encircling their wagons and protecting themselves," Sotto said.
Asked if there were inter-parliamentary measures or unspoken rules violated, Sotto said there were none.
After all, Sotto said, Duterte's accusations against De Lima involve her supposed acts before becoming a senator.
"None. I don't think the Senate has anything to do with allegations allegedly said or done when Senator De Lima was not a senator yet," he said. (READ: FULL STATEMENT: De Lima responds to Duterte's attack)
Sotto then recounted how the chamber "did nothing" when he was attacked in 1997 and 2012, at the height of the debates on the Reproductive Health bill. Sotto was a staunch critic of the landmark measure.
"The Senate did nothing when I was being attacked with black propaganda in 1997 and 2012. I was a senator then. I myself had to call for a full Senate investigation to prove that I was not guilty of allegations," Sotto said.
Senator Risa Hontiveros and the Liberal Party (LP) have urged Senate President Aquilino Pimentel III to defend De Lima's integrity.
Hontiveros said Duterte's act is "consistent" with his "disturbing pattern" of disrespect of women. It was a terrible ad hominem attack, she added.
"Kami po sa Senado tumindig kami. Itaguyod ang dignidad ng isang myembro namin sa isang maayos na paraan," she said.
(Us in the Senate, we should take a stand. Uphold the dignity of a member in the proper manner.)
The LP also denounced the President's remarks and called on Pimentel, Duterte’s ally and party mate, to uphold the chamber's independence. (READ: Robredo, LP back De Lima: Personal attacks don't help)
Senator Francis Pangilinan, an LP member, said the allegations against De Lima “are unfair.”
He said he understands that Duterte is “hard-pressed to deliver on his campaign promise to rid the nation of the scourge of illegal drugs but there ought to be a greater degree of civility in the face of disagreements between and amongst both branches of government.”
“We should be able to perform our different roles as servants of the people and accord each other due respect,” Pangilinan said.
Senate President Pimentel refused to speak on the issue. Pimentel is closely associated with the two officials engaged in the heated word war. De Lima was Pimentel's lawyer when he filed an electoral protest in 2007 while Duterte is a fellow Mindanaoan and party mate in PDP-Laban.
Senate President Pro-Tempore Franklin Drilon, De Lima's party mate in the LP, is also yet to comment on the issue.
Senator Richard Gordon, for his part, shared Sotto's sentiment, saying the disagreement is primarily a personal fight. (READ: De Lima to Duterte: Have decency to spare my friends, family)
"I don't think we should take a stand. Why should we take a stand? That's their problem in the first place. It could be personal dahil tinira niya ang death squad (because she hit the death squad)," Gordon said.
De Lima, as former justice secretary, investigated then Davao City mayor Duterte for his alleged links to the Davao Death Squad.
Gordon said it would be risky for the Senate to take a position now.
"Ang sinasabi ko why should we take a position? Eh halimbawa maglabas ng ebidensiya eh 'di mukhang ano tayo," he said.
(What I'm saying is why should we take a position? What if they release evidence? We would look silly.)
Gordon also appealed to the public to avoid making the fight a gender issue.
"Wala nang gender issues (Let's not make it a gender issue). Take it like a man," he said. (READ: De Lima hits back: Duterte 'abuses, misuses' power)
The veteran senator also defended Duterte's actions, saying that is just how local officials do it.
"You have to give him that slack and local boy 'yan.'Di dumaan sa Senado. Dumaan sa Kongreso pero 'di makatagal. As lokal 'pag tinira ka babalikan mo kalaban mo," said Gordon.
(You have to cut him some slack. He's used to local politics. He didn't go through the Senate. He became a member of the House of Representatives, but not for very long. When you're in local politics, you retaliate when someone takes a swipe at you.) – Rappler.com