Roces also rejected Mrs. Arroyo’s apology to the nation and demanded her resignation, calling it "the most honorable thing to do."
The popular actress said during an interview with GMA-7 last night that she was willing to take on the role as the nation’s leader.
"Kung kinakailangan, pangangatawanan ko at sama-sama tayo (If there is a need to, I will do so and we will all do so)," Roces said.
Roces, the widow of Fernando Poe Jr., earlier called a news conference in which she accused Mrs. Arroyo of stealing the 2004 election from her popular actor-husband, who died of a stroke last December.
"The gravest thing that you (Mrs. Arroyo) have done is that you have stolen the presidency, not once, but twice," Roces shouted during the news conference at the Club Filipino in Greenhills, San Juan.
Malacañang rejected Roces’ calls for the President to step down, saying this would be "unacceptable."
Press Secretary Ignacio Bunye maintained that Mrs. Arroyo did not cheat in the elections.
The President broke her silence Monday following a three-week-old scandal over wiretapped recordings, apologizing for her "lapse of judgment" in calling an election official about protecting a million-vote victory margin.
In a televised speech, Mrs. Arroyo apologized for her actions, denied vote-rigging and reiterated her refusal to resign.
Roces, however, said she found the President to be "insincere" during her televised speech last Monday.
She said Mrs. Arroyo did not display courage in admitting to her mistake. ("That is not) courage, but tapang ng apog na magsinungaling (the gall to tell a lie)."
"She (Mrs. Arroyo) can lie through her teeth with a straight face," she told GMA’s Arnold Clavio in the later interview.
Earlier, Roces told a news conference at Club Filipino that Mrs. Arroyo had lost the trust and confidence of the Filipino people.
Roces rejected outright the President’s apology, saying Mrs. Arroyo "has done enough damage to our country. She has put our country to shame."
Asked if she would lead protest actions to force Mrs. Arroyo’s resignation, Roces said: "We will get there. It depends how hardheaded this President is."
Cheering supporters chanted Roces’ name and showered her with rose petals as she spoke at the top of her voice, slamming the President during the news conference.
"She (Mrs. Arroyo) is arrogant. She did not consider the feelings of the majority," the actress blurted.
"She violated the law and she kept it secret. We would not have known about it if the (wiretap) tapes had not been revealed," she said.
"May kasabihan tayong mga Pilipino, Ang sinungaling ay kapatid ng magnanakaw (We have a saying in Filipino that a liar is also the sibling of a thief)!"
"I am sorry that I cannot accept your apology," she added, directing her diatribe at the President. "You eroded the trust and confidence of the people. You have no moral authority to lead."
On Wednesday, about 80 left-wing groups launched a new alliance they called Struggle of the Masses, vowing to hold nationwide street protests and demand Mrs. Arroyo’s resignation.
"I think her government has been mortally wounded," said Francisco Nemenzo, a leader of the new alliance and former president of the University of the Philippines. "The pressure will continue."
Many in the opposition want Roces to lead their fractured ranks, but she had been reluctant to assume the role.
Her press conference seemed to indicate she would now consider a leadership role, though whether as an opposition leader or as a political candidate in a legitimate electoral race was unclear.
Earlier, when the "Gloriagate" controversy first broke, Roces had called for calm and sobriety, rejecting moves to sustain pressure against Mrs. Arroyo to step down following disclosures by former National Bureau of Investigation (NBI) deputy director Samuel Ong on the wiretapped recordings.
Roces, the widow of Poe who lost by a million votes to Mrs. Arroyo in the 2004 election, had said there was "nothing to gain" by street protests since "her candidate" had already passed away.
The veteran actress, who had become a rallying point for the political opposition following the death of Poe last year, now seemed more willing to play that role following the President’s admission on Monday.
Asked if it was time for people to take to the streets, the veteran actress replied, "Umpisahan mo, tatapusin ko (You start, and I’ll finish it)," quoting one of the movie titles of her late husband.
The crowd likewise egged her on. "Usad! Usad! (Move forward, move forward)!" her supporters shouted.
Roces also rejected suggestions that Vice President Noli de Castro should assume the presidency if Mrs. Arroyo stepped down, as is dictated by the Constitution. She said the former senator and broadcast journalist always took the President’s side, whether right or wrong.
During the news conference, Roces became irritated when asked what her next move would be if Mrs. Arroyo stepped down.
"It is our countrymen who can best decide (my) fate," she replied.
A barrage of questions from assembled journalists made Roces lose her temper. When asked by the Associated Press whether she would endorse extra-constitutional means of ousting Mrs. Arroyo, the actress shot back that she had already answered the same question in an earlier briefing.
Bunye noted the news conference at the Club Filipino had been emotionally charged, egging on Roces to accept the role to lead the opposition.
"We heard her interview and we really felt her anger and frustration but we cannot agree to some of her observations. The gist of her accusations is that we cheated and we cannot accept that because the President’s victory had been predicted long before the elections," Bunye said.
Bunye insisted: "It’s the opposition that lost."
"They lost from day one because they failed to unite. They lost because the President had a clear platform of government that a majority of the people supported. There was no cheating," he said.
"We don’t know what their next move would be, especially when we felt the extreme anger when (Roces) was talking. All we ask now is for people to remain calm and not be carried away by emotions," Bunye said.
Bunye called on Roces and the opposition to respect and follow the rule of law.
Vice President Noli de Castro likewise called for sobriety, and warned against mob rule. "We have to be sober on these issues and discover the truth in line with the constitutional processes," he said.
Senate President Franklin Drilon also called for sobriety as the political opposition stepped up its attacks on Mrs. Arroyo.
Drilon claimed he understood the sentiments of Roces but warned she might be submitting herself to the whims of opportunists seeking mob rule.
"We will not accomplish anything with anger. We have to remain calm and follow the processes under (the) law for an orderly society," Drilon said.
"I understand the frustration of the opposition. It is the duty of everyone to make sure that the process established by the Constitution will work or else we’ll have anarchy," he said.
Drilon said Mrs. Arroyo had already answered all the issues surrounding the wiretapped recordings.
"She (Mrs. Arroyo) maintained that she won fair and square. There is a constitutional process of determining the winner of that election. She went through the process," he said.
On the other hand, opposition Sen. Aquilino Pimentel Jr. said Roces’ statements "had made things more complicated" for Mrs. Arroyo.
Pimentel said Roces would now become the rallying point of the opposition to force Mrs. Arroyo to step down. "The President should resign or face ouster," he said.
Sen. Juan Ponce Enrile said the apology offered by the President is not enough to end the controversy over the tapes.
"It will not end there," Enrile said. " This will continue until it will finally be resolved legally. The choice for us is: are we going to follow a constitutional path or a revolutionary path? That is the basic issue now."
He said Roces would likely accomplish what Estrada failed to do in galvanizing the opposition forces toward a common objective.
According to PNP directorial staff chief Deputy Director General Avelino Razon Jr., there was nothing seditious in her statements during the press conference at Club Filipino.
"We respect the statement of Ms. Susan Roces-Poe," the former Metro Manila police chief said.
Razon noted Roces did not even initiate legal moves to oust Mrs. Arroyo from office.
"In my understanding, there was no point that she made any seditious statement. All she called for was the resignation of President. Although she was asked if she would lead civil disobedience or people power, she answered, hindi yan galing sa kanya (that did not come from me)," Razon added.
Razon said Roces "must support her allegations with evidence."
Razon made the statement after plainclothes policemen were spotted among the journalists covering the news conference of Roces. Some detectives even mixed in with opposition supporters during the event.
The lawmen were spotted taking pictures and video footage of the media people covering the event. - With Aurea Calica, Marvin Sy, Cecille Suerte Felipe, Jerry Botial, Mayen Jaymalin, AP, AFP