MANILA, Philippines -- (UPDATE) Saying he was obeying the dictates of his conscience, former speaker Jose de Venecia Jr. formally endorsed on Wednesday the impeachment complaint against President Gloria Macapagal-Arroyo filed by his son, Jose III, and vowed to tell all if called to testify should the case go to trial.

"I have come today to endorse the impeachment complaint…I believe it is a crime against the Filipino people if we do not act on the impeachment," he said, showing a copy of the complaint that he handed to the House Secretary General Marilyn Yap.

The complaint is the fourth against Arroyo, De Venecia's former political ally. He acknowledged that he was not supportive of the last three complaints, but that he has now changed his views.

"We should not be blinded by silver and gold and pork barrel," he said amid the "rampant and deep-seated corruption exploding everyday," pointing to the national broadband network deal scandal, the fertilizer fund scam, the generals caught in Russia with a huge amount of undeclared cash, and human rights violations.

"There are so many things in life that I regret. I am now 71. I think conscience dictates that we must do our duty to the people," De Venecia said.

The former speaker said he is willing to testify about the things he knows that could pin down Arroyo.

He called on the House leadership and the justice committee to allow the impeachment process to proceed and not to kill it by declaring that the complaint is not sufficient in substance, as was the case of the three earlier complaints against Arroyo.

The justice committee will begin hearing on the complaint on November 18.

An impeachment complaint needs the votes of one-third of the House before it can go to the Senate for trial.