MANILA, Philippines - Former Ilocos Sur governor Luis "Chavit" Singson on Monday said he has already resigned as provincial chairman of the ruling Lakas-Kampi-CMD party after endorsing the candidacy of Nacionalista Party (NP) standard-bearer Manny Villar.

Singson said he made the decision to leave the party on Saturday after announcing that he is not backing the candidacy of Lakas-Kampi presidential bet Gilbert Teodoro. He did not say if he is joining the Nacionalista Party.

"I have not been attending the metings of Lakas for a long time. It is unfair to Gilbert Teodoro if I announce it later on so I might as well announce it now so he can find a replacement for us in Ilocos Sur," he said in an ANC interview.

Asked if he had formally submitted his resignation, he replied: "Hindi na. In-announce ko na lang. I confirm it."

Singson, who is running for re-election as Ilocos Sur governor, said he has yet to speak to Teodoro about his decision but said his decision to endorse Villar is final. "Naka-decide na ako eh. It's useless siguro na mag-usap kami," he said.

He said he decided to endorse Villar since he has known the Nacionalista bet for a long time. He also confirmed that other Lakas-Kampi party members are also mulling the possible endorsement of Villar.

"Mas matagal na kasi sa politics si Villar. Mas marami siyang kilala. Kagaya ko, ngayon ko lang nakakausap si Gibo Teodoro pero si Villar a long, long time ago...yun ang isa sa mga nag-ano sa akin. Nung impeachment, nakatulong din sa akin si Villar. Nung impeachment nung kay Erap (Estrada)," he said.

Villar transmitted the impeachment complaint against President Joseph Estrada to the Senate before losing the speakership of the House of Representatives. Singson testified in the impeachment trial and accused Estrada of pocketing billions of pesos in illegal numbers games and tobacco excise tax kickbacks.

Estrada's impeachment trial and ouster after a 4-day bloodless revolt allowed then Vice-President Gloria Arroyo to take over as President.

'GMA not backing Villar'

Singson, meanwhile, said President Arroyo was instructing Lakas-Kampi members to back Teodoro's candidacy amid rumors that the President was secretly backing Villar.

"In fairness to the President, pinipilit kami para kami mag-open para kay Gibo so ayaw ko naman dayain sila so sinabi ko nang decided na ako once and for all, magbitaw na lang sa Lakas-Kampi," he said.

He said that while he is backing Villar, he has yet to announce his choice for vice-president. He also said that he will not endorse all the senatorial candidates of the Nacionalista Party.

Singson's announcement came after a series of "defections" by key Lakas members who have chosen to support Villar.

Villar placed second in the latest Social Weather Stations (SWS) survey while Teodoro has not made significant gains since launching his bid for the presidency last year. (Read: Aquino opens up lead versus Villar--SWS)

'Gibo: Chavit a big loss'

Last Saturday, Teodoro Jr. said losing former Ilocos Gov. Chavit Singson's support was a "big loss" to his presidential campaign, but that it won't hurt his chances with Ilocano voters.

"Manong Chavit in Ilocos Sur, if ever, is a big loss. However, I will always rely on my personal relationshup with the Ilocano people," Teodoro told reporters in Cebu. (Read: Gibo on Chavit's defection: 'It's a big loss')

Francis Manglapus, Lakas secretary-general, earlier said they had been expecting Singson's defection for some time. “It’s not totally unexpected. We have had information that he was leaning towards that…We are prepared for this,” he said.

Singson has not filed an official letter of resignation, but Manglapus said they can "quickly replace him" if he does.

He said Teodoro still has a solid base of support in Ilocos Sur, especially since the provincial governor, Deogracias Savellano, is still loyal to the Lakas standard-bearer. "We still have the current governor who is behind Teodoro," Manglapus said.

Teodoro still reportedly enjoys the support of "the Northern alliance", composed of at least 40 provincial governors.