Aquino said Mrs. Arroyo should "make the supreme sacrifice" for the sake of the country and that all the alternatives would hurt the country.
Aquino said she had no choice but to speak up despite Sundays statement by the Catholic Bishops Conference of the Philippines (CBCP) that it would not join calls for Mrs. Arroyo to quit.
"When Ninoy gave his life for us, I also dedicated my life to the nation," Aquino said.
Malacañang officials said they respected Aquinos position but maintained that Mrs. Arroyo broke no law and therefore had no reason to resign.
"We believe that the President has not committed any illegal (act), anything in violation of the Constitution. Thats why we respect the decision of the President not to resign but she welcomes other constitutional means to settle issues (against her)," said Press Secretary Ignacio Bunye.
Malacañang also appealed to political groups and various sectors to respect the decision of the CBCP, saying the administration will consider the proposals, including the formation of a truth commission to investigate the charges against the First Family.
"The CBCPs position will somehow douse the prevailing political tension and help enlighten all of us," Bunye said.
"Whatever our political persuasions, we call on the political groups and various sectors concerned to respect the bishops stand," he said. "We are prepared for all constitutional and lawful means to resolve outstanding issues."
Bunye said the CBCP statement would surely alleviate the anxieties of various sectors of society but noted the President would not stop working hard to implement the necessary reforms cited by the bishops.
"We believe this is all for the best. The President is intent on implementing key reforms as a result of this situation," he said.
For his part, Vice President Noli de Castro was mum over Mrs. Aquinos renewed call for the President to resign.
Lawyer Jesse Andres, De Castros chief of staff, said the Vice President declined to comment on Aquinos renewed call made yesterday at La Salle.
Aquino said there were only two constitutional options to end the current political crisis resignation and a handover of power to De Castro, or impeachment.
Impeachment "can only generate more divisions in society and cast more suspicion on the threatened institutions of our democracy," said Aquino, who was one of Mrs. Arroyos closest allies before urging her to resign last Friday over the political scandal.
"I ask the President to spare our country and herself from this second option and make the supreme sacrifice of resigning."
On the other hand, Justice Secretary Raul Gonzalez belittled Mrs. Aquinos influence to oust Mrs. Arroyo, saying former President Fidel Ramos is the "key" that will let the President stay in power.
At a press conference, Gonzalez said Ramos carries a lot of weight compared to Mrs. Aquino when it comes to influencing the people to oust Mrs. Arroyo. But he belied speculations that Ramos is now the de facto president.
"I think FVR (Ramos) carries a lot of weight over Aquino because President Ramos has definitely the allegiance, I would say, of the men in uniform. I dont think Cory has that," he said.
Mrs. Aquino made the call after a special Mass for "enlightenment" called by De La Salle University, which had also pressed for Mrs. Arroyos resignation on moral grounds.
Aquino, joined by Mrs. Arroyos former Cabinet officials including ex-finance secretary Cesar Purisima, was met with applause from students who packed the university chapel.
La Salle officials said they would invite members of the political opposition in coming days to engage in dialogue.
Mrs. Arroyo is clinging to power after 10 senior officials quit her Cabinet on Friday and urged her to do likewise. She has apologized for what she called a "lapse in judgment" after calling a senior election official during the May 2004 vote but has denied stealing last years presidential election.
"Ours is a plea and a prayer that she voluntarily relinquish power so that a constitutional process of succession may proceed. It is a non-violent appeal to her conscience for the good of the nation," said Bro. Armin Luistro, La Salle president.
"It pains me to tell her this simple truth, but we do so in all charity, with deep humility and with resentment toward none," he said.
Luistro said calling for the Presidents resignation was "a painful choice."
"Some of us have been victims of a well-orchestrated demolition job to silence our voice. At least one in the family received veiled threats," he said.
Rigoberto Tiglao, one of Mrs. Arroyos chief aides, accused Aquino of "intellectual dishonesty" and said the President "never will resign."
"Were talking here not only of this presidency, but the future of this country," Tiglao said. "Demand for the President to resign is really an attempt to move other political forces to force the President to resign."
Mrs. Arroyo has defiantly refused to step down and challenged the opposition to file an impeachment case against her in Congress, claiming they were trying to circumvent the countrys democratic institutions.
An impeachment complaint has been filed against her amid allegations she cheated in last years election.
Last Sunday the CBCP, the Catholic Churchs local policy-making body, refused to back calls for her resignation, though it said she could still do so if it would resolve the situation. The military and police have resolved to uphold the law and protect the presidency, while former President Ramos, seeking a transition to a unicameral parliamentary form of government, has also stood by Mrs. Arroyo.
Opposition and left-wing groups will press ahead with protests calling for Mrs. Arroyos resignation, though, undeterred by the CBCPs refusal to join them.
Mrs. Arroyo has expressed gratitude to the bishops for their crucial stand, which may ease the raging political crisis. However, groups seeking her ouster continued to urge the clergymen to change their position.
"They acted like Glorias apologists," priest-activist Robert Reyes, who is fasting to pressure Mrs. Arroyo into resigning, said of the bishops statement. "They should always guide the flock but theyre just sowing more confusion."
Renato Reyes, secretary general of the left-wing group Bayan, said that while the bishops did not directly call for Mrs. Arroyo to step down, they did concede that groups were free to continue seeking her ouster and peacefully expressing their outrage at the allegations.
"Arroyo is digging in. We think the decisive factor would be for people to fill the streets in large numbers to force her out," he said.
Lingayen-Dagupan Archbishop Oscar Cruz, who is leading an anti-jueteng crusade that has implicated Mrs. Arroyos husband, son and brother-in-law, said the CBCP could still change its mind later "if other matters are exposed, if there is a change in circumstances or if reforms are not made."
A CBCP council meeting is scheduled in September. Cruz said the CBCP could also hold special or emergency meetings if necessary.
While a number of protests were scheduled Monday and Tuesday, anti-Arroyo groups were bracing for a huge rally Wednesday in Makati Citys financial district, where they planned to wear white to symbolize their concerns for the truth.
The carefully worded bishops statement titled "Restoring Trust: A plea for moral values in Philippine politics" was far from an endorsement of Mrs. Arroyo, calling for greater accountability and saying the election scandal had undercut public trust.
The bishops said there was no clear solution and Mrs. Arroyo must decide for herself if the damage from the crisis is fatal to her leadership.
However, they noted her resignation would not end the political divisions that it has laid bare.
"We ask the President to discern deeply to what extent she might have contributed to the erosion of effective governance and whether the erosion is so severe that its irreversible," the statement said. "She has to make the necessary decision for the sake of the country."
The bishops also called for establishment of an independent "truth commission" to probe the election allegations, and suggested she could face impeachment proceedings. With Evelyn Macairan, Paolo Romero, Jose Rodel Clapano, Mike Frialde, Sheila Crisostomo, Eva Visperas, Sandy Araneta, Jess Diaz, Jaime Laude, Mayen Jaymalin, AFP, AP