"Nabasa ko na naman ang iyong pahayag na tinatawag mo ang mga pro-Duterte senators na mga duwag. Alam mo Ginoong Trillanes, kung binabasa mo lang ang ating rules ng senado, hindi ka dapat magsalita laban sa kapwa mo senador. That is totally uncalled for, lalong lalo na tinawag mo silang duwag," he wrote.
Estrada recalled the time when Trillanes walked out from a debate with former Senate President Juan Ponce Enrile.
"Duwag kamo? Kung naalala mo nuong nakipag-debate ka kay Senate President Enrile, diba nag walk-out ka sa kalagitnaan ng debate dahil wala kang maisagot sa mga tanong ni SP Enrile? Sino ngayon ang duwag? Maliwanag pa sa sikat ng araw na ikaw ang pinaka-duwag sa lahat ng mga senador na nakasama ko," he said.
The former senator also defined the word 'cowardie' in case the mutineer turned senator doesn't know.
"In case you don't know the meaning of cowardice Sen. Trkillanes. Let us define clearly the definition of cowardice. Accdg to Webster dictionary, it is lack of courage or firmness of purpose."
Estrada mocked the coup d'etat Trillanes organized during the Presidency term of Pampanga Rep. Gloria Arroyo in which Trillanes and fellow Magdalo mutineer, Danilo Lim, surrendered several hours later.
"Remember the coup de etat that you staged in the Manila Peninsula? If you were really firm and had the courage to fulfill your mission, then you shouldn't have surrendered. Nakarinig ka lang ng mga putok ng baril galing sa mga pulis, unang-una ka nag surrender! Ano tawag mo dun? Diba, act of COWARDICE yun? Now please tell me Sen. Trillanes, sino sa mga kapwa senador mo ang mga duwag? Malamang kapag nagbanggit ka ng pangalan, di ka nila lulubayan sapagkat wala akong kilalang duwag na senador ngayon maliban sa iyo!!" Estrada wrote.
Estrada then ended his letter to Trillanes by telling him to just keep his mouth shut if he doesn't have anything good to say. He told Trillanes should RESIGN from thee Senate, which he described to be one of the "most damaged institutions in the government" because the Senate does not his kind.
"Kung wala kang magandang sasabihin sa mga kapwa mo senador, you better just keep your mouth shut!
The guts to even say that the Senate in which you belong , is one of the most damaged institutions in the government! How dare you say that! So, what are you waiting for? Better RESIGN now. Honestly, the Senate doesn't need senators who are certified cowards like you!"
Few days ago, Senator Panfilo Lacson also striked back at the 'coward' Senator Trillanes for berating the Senate. He said that the latter has lost his touch of reality if he is not hallucinating. Lacson said he's not sure whether his colleague is still thinking rationally.
Trillanes commented on the recent mockery of Trillanes where he said that the Senate is now just a mere puppet of Duterte for refusing to investigate the current administration's abuses.
He claimed that the Senate's supposed role as the "last bastion of democracy" and now went down to just being pawn.
"Itong Senado na dati ay ‘yan yung last bastion of democracy eh ngayon, wala na, para na rin kaming mga tuta nitong administrasyon na ’to. Ni ayaw mag-imbestiga eh," Trillanes said in a presscon.
"Dito ako makakakita ng mga senador na takot, kaalyado ka na lang kasi ayaw mo aminin na takot ka eh," he added.
According to the former mutineer, there are some chairpersons of Senate committees who refuses to do their job in castigating the so-called abuses of the current administration.
"Yung mga dapat sana na pumuna eh wala eh, sila yung mga bahag ang buntot," he said, although not pinpointing any of his fellow senators. "Dati, professionalized ang hanay ng kapulisan pero dahil inengganyo magpatay (sic) ng tao eh ngayon, d’yan sa hanay ng kapulisan, may mga mamamatay tao eh. Eh papaano yan, papaano madi-displina later on?" he said.