Philippine President Rodrigo Duterte speaks during the annual state of the nation address at the House of Representatives in Manila. Photo: AFP

Philippine "First Daughter" Sara Duterte on Saturday entered the vice presidential race for the 2022 elections, in a surprise move that could boost the chances of presidential hopeful Ferdinand Marcos Jr winning the country's highest office.

Outgoing President Rodrigo Duterte, who is constitutionally barred from seeking a second term, also flagged plans to contest the vice presidency - triggering chaotic scenes at the Commission on Elections office handling last-minute changes to candidacies ahead of a November 15 cutoff.

The elder Duterte "will file his certificate of candidacy for the vice presidency on Monday, that's what he said," presidential communications chief Martin Andanar said.

But he added: "I would like to believe that that is the plan for now. We don't know if this will be the same plan by tomorrow or by Monday."

Sara Duterte, 43, had been widely expected to seek the presidency in a bid to succeed her father, and potentially protect him from criminal charges in the Philippines and International Criminal Court investigators probing his drug war.

Her tilt for the country's second-highest office was immediately endorsed by the party of Marcos Jr, the son and namesake of the former leader, to be his running mate in the poll. 

"This is to confirm that Mayor Inday Sara Duterte through her representative, has filed her Certificate of Candidacy for Vice President under Lakas-CMD [party]," her spokeswoman Christina Garcia Frasco said on Facebook, confirming the Commission on Elections' announcement. 

AFP