Escudero said he formalized his Senate bid ahead of his opposition teammates "to dispel rumors that the opposition is disintegrating and that one by one, we are jumping to the administration’s camp."
Escudero was accompanied by his wife Christine and actress Susan Roces, the widow of Fernando Poe Jr., when he filed his candidacy at the Commission on Elections.
Escudero belongs to the Nationalist People’s Coalition (NPC), the political party founded in 1992 by businessman Eduardo Cojuangco Jr.
"I am with the opposition and I will remain with it," Escudero said, adding that he had declined an offer to join the administration slot.
"I filed my certificate under NPC, my party since 1998 (when he first became a congressman)," he said.
He is one of the two opposition leaders in the House who are expected to land slots in the opposition senatorial ticket. The other is Deputy Minority Leader Alan Peter Cayetano.
Escudero lamented that since Senators Vicente Sotto III and Teresa Oreta broke away from the camp of ousted President Joseph Estrada last week, the administration and its allies have been claiming that the opposition is crumbling.
"We remain largely united and we will field a complete formidable ticket," he said.
"Expect other opposition candidates to follow soon," he added.
Sotto and Oreta are now Escudero’s party mates in the NPC. But there are speculations that the two former senators will eventually join the administration senatorial ticket.
The two are included in the so-called unity slate that President Arroyo’s chief of staff Mike Defensor is trying to put together. Also in that lineup, according to Defensor, is former First Lady Imelda Romualdez Marcos.
Roces, in a separate interview, said she joined Escudero in filing his candidacy for personal reasons.
"My presence is because of our relationship as godmother and godchild," she said.
Roces said she would always back the candidates who supported the presidential bid of her husband.
She also maintained that uniting the opposition at this time would be difficult.
"It looks like very impossible with the way things are going now," Roces said.
In a related development, Muntinlupa Rep. Rozzano Rufino Biazon said he would rather seek re-election than run for senator.
Biazon, son of Sen. Rodolfo Biazon, is one of six candidates for senator nominated by the Liberal Party.
He said he was humbled by the nomination but that he preferred to be re-elected so he could finish his projects in his district.
"Another reason for declining the nomination is my personal stand that two Biazons in the same chamber is not ideal for two reasons: we will be able to more effectively push for our common legislative agenda if we are in separate Houses, and we do not want to add to the discussion about the Senate being a family affair," he stressed.