MANILA, Philippines—(UPDATE 4) Senator Benigno “Noynoy” Aquino III finally broke his silence and announced he would join the 2010 presidential race to continue the work of his famed mother, who played a crucial role in overthrowing dictator Ferdinand Marcos.

The announcement came following a highly-publicized spiritual retreat and made on the 40th day of former president Corazon Aquino’s death Wednesday, as the family ended the traditional period of mourning.

“I accept the plea of the people. I accept the advice of my parents. I accept the responsibility to continue the fight for the people. I accept the challenge to lead in this fight. I will run in the coming elections,” Aquino, 49, told a crowd of cheering supporters.

Vowing to fight against corruption that pervades the nation, Senator Aquino said he would be a leader for all sectors of society and not just the rich.

"I will be there because of the people, I will stay there because of the people and hopefully I will be true to my word to serve the people," he said.

Aquino made the announcement at Manila's historic Club Filipino, where his mother, Corazon, was sworn in as president in 1986 after leading the "People Power" revolution that ended Marcos's 20-year reign.

Senator Aquino’s sisters—Ballsy, Pinky, Viel, and Kris—were also there. They were all wearing black as was the senator.

Aquino, however, could not say yet who would be his running mate.

At a press conference after the announcement, Aquino declined to say if Senator Manuel “Mar” Roxas would join his ticket as vice president, saying he would just let the former trade and industry secretary make the decision himself.

“I offered the vice-presidency slot to him, am waiting his decision” he said.

Roxas, Aquino’s colleague at the Liberal Party, surprised the public when he dropped his presidential bid early last month to give way to Aquino.

Aside from Roxas, two other opposition presidential hopefuls—Makati City Mayor Jejomar Binay and Pampanga Governor Eddie Panlilio—have announced to stand down and offer their support.

This leaves Aquino with the task of getting deposed president Joseph Estrada and Senator Manny Villar, the two aspirants currently leading in the polls, to fall behind him to ensure the opposition vote is not split.

The ruling coalition of President Gloria Macapagal-Arroyo, who is barred by the constitution from seeking a new six-year term, has yet to announce its candidate ahead of the November 30 deadline for filing candidacies.

Aquino's Liberal Party has been a fierce critic of Arroyo, alleging widespread corruption in her administration.

Arroyo's spokesman Lorelei Fajardo conceded Aquino has emerged a strong contender for the presidency, while calling him a "welcome addition to the race."

But Estrada, the 72-year-old former movie star who spent time in prison after he was toppled in a bloodless 2001 military coup and convicted of corruption, said the opposition should let the electorate decide.

The choice was not for "the elites and the bourgeois" to make, he said, in a dig at the Aquino camp.

Binay, however, said he was giving way to Aquino "to pave the way to uniting the opposition."

Aquino's decision also opens the tantalizing prospect of a two-way race for the presidency against his first cousin, Defense Secretary Gilberto Teodoro, who is a leading candidate to run for the ruling coalition.

Prior to his mother's death, the bespectacled, balding Aquino was best known as a low-profile politician with no major legislative achievements after nine years in the House of Representatives and two in the Senate.

He was better known as the former boyfriend of a broadcast journalist, Korina Sanchez, and the brother of TV celebrity Kris Aquino.

Aquino said he only began seriously considering a presidential bid after seeing the massive outpouring of support for his family following his mother's death from cancer.

People across the country mourned former president Aquino’s passing and hundreds of thousands poured into the streets to pay their final respects to the country’s “Icon of Democracy.”

Soon, grief turned into a campaign for Senator Aquino to carry on the work of his mother.

Aquino said he would rely on the help of ordinary Filipinos to become president, just as they propelled his mother to power.

"The reason why I am on this path is because I believe the public will support and help me in the campaign," he said.

"I want to make democracy work not just for the rich and the well-connected, but for everybody."

His father, martyred senator Benigno Aquino Jr., is held in equally high esteem by many throughout the Southeast Asian nation of 92 million people.

As then opposition leader, Marcos gunmen shot him dead at Manila airport in 1983 as he returned from exile.

His assassination led to Cory reluctantly moving into politics and becoming president for six years, a period that has been widely acclaimed for restoring democracy after a generation of martial law.

Senator Aquino called on Filipinos to recall his mother's achievements when they considered who they wanted to be their next president.

"During my mother's time, she was not corrupt. Even the policeman on the street had second thoughts of being corrupt," he said.

Nevertheless, his family belongs to one of the powerful clans that have dominated Philippine life for generations, and observers have pointed out that a win for Aquino would be another victory for the elite.

Corazon Aquino's cousin, Eduardo Cojuangco, is majority owner of brewing giant San Miguel and, according to the latest Forbes rich list, the seventh wealthiest man in the Philippines.

With Senator Aquino’s formal declaration to run for President came offers to volunteer and even raise funds for his campaign.

After the announcement, former Secretary Karina David said she was swamped with text messages from "non-political'' friends inquiring about how they could pitch in in Aquino's campaign.

According to the former Civil Service Commission chair, the messages ran the gamut of "Ma'am, we want to volunteer," "We are with you," "What can we do?" and "My entire family wants to help.''

Political analyst, UP Political Science Professor Clarita Carlos, meanwhile, said it was too premature to conclude that Aquino could bring together personalities, parties and civil society groups to support his campaign in the “afterglow'' of his mother's death.

Between now and May 2010, the first-term senator has to deal with the “realpolitik forces in the country,” and many “imponderables” such as political realignments, campaign funds, and volunteers, she said.

“Everything is in the realm of conjectures. The elections is 10 months away. A lot of things can happen,” she said by phone, asking: “Will the afterglow be sustained and translated into votes? Will it galvanize the collective consciousness to support this person?”

There are no easy answers, she said.