MANILA - Congress proclaimed Vice President-elect Leni Robredo on Monday, sealing a stunning victory that thwarted the bid of Sen. Ferdinand Marcos Jr. to reestablish his family's influence in national politics.

Wearing a simple black and white dress, the 51-year-old grassroots lawyer and Camarines Sur Representative was declared the winner of the vice-presidential race at the House of Representatives to loud applause from her colleagues.

Robredo trounced the only son and namesake of the late dictator, Ferdinand Marcos, by just 263,000 votes. A vice presidential win would have been the young Marcos' springboard to recapture Malacanang in 2022, according to analysts.

"Official na tayong Vice President-elect, yung na-hurdle na natin yung pinakamahirap na bahagi. Pero yung mag susunod na mga araw, susunod na mga buwan, susunod na anim na taon ay kailangan na kailangan ko pa kayo," Robredo addressed supporters after her proclamation.

Robredo polled at just single digits before the start of the campaign, a reluctant candidate after Sen. Grace Poe declined to run as vice president to former interior secretary Mar Roxas, the preferred successor of outgoing President Benigno Aquino.

During one of the vice-presidential debates, Robredo trended on social media after she declared that "the last man standing is a woman."

Roxas and Poe lost to President-Elect Rodrigo Duterte, who skipped his own proclamation on Monday.

Before her proclamation, Robredo heard mass with supporters at nearby church, where she appealed to Marcos to accept defeat.

Marcos, whose six-year term in the Senate ends on June 30, is considering filing an electoral protest, according to his lawyer.

"Hindi lang naman ako iyung biktima ng ginagawa nila, hindi lang iyung 14 million na bumoto sa amin, kundi buong sambayanan. Sana mag-move on na tayo," said Robredo.

Robredo was first thrust into the national spotlight after her respected politician-husband, then interior secretary Jesse Robredo, died in a plane crash.

It was on her husband's birth anniversary last Friday that the official canvass ended.

Robredo is the country's 14th vice president, the second woman to hold the post after Gloria Macapagal-Arroyo and the first from the Bicol peninsula.