MANILA (UPDATE) - President Rodrigo Duterte has formally accepted the nomination of a PDP-Laban faction for him to run for vice president in next year's elections by signing a relevant document, the party's Cusi-led faction said Thursday.

Duterte signed a certificate of nomination and acceptance (CONA), which carried the PDP-Laban letterhead and logo and indicated the date of Sep. 17, 2021, according to a copy of the document released by Melvin Matibag, Secretary-Genaral of the PDP-Laban wing led by Energy Secretary Alfonso Cusi.

• Duterte accepts VP endorsement by PDP-Laban in 2022 polls

In a statement, PDP-Laban said it was confident that Sen. Christopher Lawrence “Bong” Go would agree to run as the party's presidential candidate after Duterte accepted his nomination as vice-presidential bet.

"We’re still waiting for Sen. Bong Go to accept. We hope the action of the President would help Sen. Go to decide on his nomination soon," Matibag said.

Go, Duterte's longtime aide, earlier declined the nomination of the PDP-Laban Cusi-wing to be their presidential candidate.

The party, in the statement, stressed that it was not considering any other presidential candidate as a substitute for Go.

Matibag said the ruling party would sign a formal alliance with national party Pederalismo ng Dugong Dakilang Samahan (PDDS) on Thursday.

PDDS' party president is Presidential Anti-Corruption Commission (PACC) Chairman Greco Belgica, who is included in PDP-Laban's senatorial ticket.

Similar agreements are also being forged with several local parties, Matibag added.

The Commission on Elections has yet to determine which of the two factions of the ruling party - the other being the one led by Senators Aquilino "Koko" Pimentel III and Manny Pacquiao - is the legitimate PDP-Laban.

The party was founded by Pimentel's late father Aquilino Pimentel Jr.

• 2 party filings: Pacquiao-Cusi feud over control of PDP-Laban enters Comelec
• Comelec: PDP-Laban fielding 2 presidential bets in 2022 'possible'

The filing of certificates of candidacy for the May 9, 2022 polls will run from Oct. 1 to 8. Candidates who fail to submit a CONA signed by officials of the Comelec-recognized party will be deemed as independent bets.

"Doon sa tanong na wala na bang pagbabago, tingnan po natin kung anong mangyayari sa Oct. 8, saka Nov. 15," Duterte’s spokesman Harry Roque said of the President’s election plans.

(On the question if will anything change, let us see what will happen on Oct. 8 and Nov. 15.)

Those hoping to substitute for their party or coalition allies who will back out of the race can file certificates of candidacy until Nov. 15.

Last Sunday, Pacquiao, 42, formally announced he would run for President next year after accepting the nomination by partymates in his faction.

• Pacquiao accepts PDP-Laban faction's nomination, launches 2022 bid for presidency

Duterte, 76, had earlier said the public should "consider" him as "a candidate for the vice presidency" in next year's polls.

He said he would run for the country's second-highest post to achieve immunity from lawsuits, which critics said was only applicable to the President.

• Duterte: 'Consider me as a candidate for VP at this time'
• ‘Tatakbo na lang ako’: Duterte will run for VP if it means having legal immunity

Last week, the International Criminal Court said it would investigate Duterte and his war on drugs, and the killings in his hometown Davao City from November 1, 2011 to June 30, 2016, when he served alternately as mayor and vice mayor.

• ICC Pre-Trial Chamber greenlights probe on PH drug war, Davao killings

An election lawyer had said Duterte's vice presidential bid would deprive others of equal access to public service.

“Hindi naman pwedeng sila lamang ang nakakaalam kung ano ang dapat gawin sa ating bansa. Ang sabi ko nga, maliwanag sa ating Saligang Batas, dapat ang paglilingkod sa ating bansa binibigyan din ang ibang tao ng oportunidad, equal access to public service,” Romulo Macalintal said in a previous interview.

(They are not the only ones who know what is right for the country. It’s clear in the Constitution that there should be equal access to public service.)

• Election lawyer: Duterte's VP bid to deny others equal access to public service

Senate President Vicente "Tito" Sotto III and Dr. Willie Ong have also announced they would join the vice presidential race next year, in tandem with Sen. Panfilo "Ping" Lacson and Manila Mayor Isko Moreno Domagoso, respectively.

• Isko Moreno and Willie Ong declare bid for 2022 election
• 'Ito ang simula': Lacson, Sotto launch 2022 bid, vow to restore order, trust in PH

Watch more in iWantv or TFC.tv