Retired senior associate justice Antonio Carpio is urging the Supreme Court to recognize and accept what he has argued are factual and legal mistakes in nullifying the articles of impeachment against Vice President Sara Duterte, and to reverse its ruling in good faith.

Carpio, who served 18 years on the Supreme Court, is a founder and lead convenor of the political coalition 1Sambayan, one of the challengers of the tribunal’s July 25 ruling that declares Duterte’s impeachment unconstitutional.

The ruling upholds two petitions against the impeachment, including one filed by Duterte herself even after she had declared she was gearing for a “bloodbath” in a trial. Carpio and 1Sambayan’s omnibus motion seeking a reconsideration of the ruling is focused on debunking the two main grounds that the tribunal cited for its decision: the constitutional bar to more than one impeachment proceeding against the same official within a year and the lack of due process.

In all, four impeachment complaints were filed separately in the House of Representatives against the Vice President for betrayal of public trust and other high crimes—three in December 2024 and the fourth on Feb. 5, which eventually constituted the articles of impeachment that were transmitted to the Senate.

‘Factual error’

In an interview on Monday with CoverStory, Carpio said one ground for 1Sambayan’s opposition to the ruling is the “factual error” in the tribunal’s finding that the first three complaints were “deemed initiated,” thereby blocking any subsequent impeachment proceeding until Feb. 6, 2026.

He and his group cited a landmark Supreme Court decision’s definition of an “initiated” proceeding as one where the complaint had been included in the order of business within 10 days after it was filed and then referred to the House committee on justice within three days after that.

The official journal of the House shows that the December complaints never reached this stage, rendering the tribunal’s factual basis for the one-year bar incorrect.

Carpio said that according to the Supreme Court, the articles of impeachment were transmitted to the Senate for trial “even without a plenary vote.”

“This is, of course, contrary to what actually happened based on the journals,” he said.

The plenary in fact voted close to 4 p.m. on Feb. 5 to approve and transmit the fourth complaint to the Senate after it was signed by 215, or more than one-third, of the House members, Carpio pointed out. The Senate received the articles of impeachment around 5 p.m. The plenary vote was unanimous. “There was no objection,” he said.

After that, the plenary voted to archive the first three complaints and then the House selected the members of its impeachment prosecution team for the upcoming Senate trial. The House adjourned at 7:15 p.m. on the same day.

“So clearly there was a plenary vote and it happened before the adjournment, before the archiving of the first three complaints,” Carpio said. “So, there is a factual error in the statement of facts in the resolution [of the Supreme Court].”

“It’s very clear that there was a plenary vote. So, if they’re in good faith, they should reverse [the decision],” he said.

Carpio said there is also “inherent inconsistency” within the tribunal’s resolution where it says in one part that there was no plenary vote, but states “a few pages later” that there was, pointing to the citations to the vote by the two petitions against the impeachment.

‘New’ guideline

The 1Sambayan’s second major objection to the ruling is the “new” due process guideline imposed by the tribunal on all the stages of the impeachment process in the House, before the impeached official faces the Senate acting as an impeachment court that will review prosecution and defense evidence.

Carpio observed both constitutional and practical problems against the seven-point guideline.

Under the new rule, the House must give a copy of the draft articles of impeachment to the official being impeached, who has the right to answer the charges and demand a hearing at the plenary level, or before all the House members numbering more than 300. 

According to Carpio, the new rule would be “impossible to comply with physically,” especially under the second mode of impeachment where the articles of impeachment are sent immediately and directly to the Senate once these are endorsed by at least one-third of the House.

The Constitution does not provide for a hearing in that mode of impeachment.

The other mode calls for deliberation on the merits of the impeachment complaint in the House committee on justice before its members vote to approve or reject it.

Carpio said it would be “so unwieldy” for an impeachment deliberation, or any other inquiry for that matter, in the plenary, which is why all investigations by the House are always conducted by the relevant committees.

He said no such seven-point due process rule is required in the Constitution and in two landmark Supreme Court rulings on impeachment—Francisco v. House of Representatives (2003) and Gutierrez v. House of Representatives (2011).

Justifying the new rule, however, the Supreme Court said the constitutional provision on impeachment does not exist in isolation of the other provisions and is therefore subject to due process of law.

Making impeachment ‘impossible’

A third ground Carpio et al. are citing against the Supreme Court’s ruling is the retroactive application of this new rule on the House, which, the retired justice said, had acted in good faith in following the Constitution and existing jurisprudence established by Francisco and Gutierrez.

Since the House did not comply with these due process requirements, the articles of impeachment are void, according to the Supreme Court.

But Carpio said: “Nobody in the world could comply with a rule that does not exist. We’re saying that these new rules, if you apply them, will make the impeachment impossible.”

Enforcing these requirements on the House would violate due process itself “because before you are bound by a rule, you must have actual notice of the rule, or constructive notice,” said Carpio, who is also a champion of the Philippines’ sovereign rights in the West Philippine Sea in the maritime dispute with China.

He said the Supreme Court couldn’t have jurisdiction over the impeachment process due to its erroneous factual basis in finding that the three impeachment complaints against Duterte had been “initiated,” thus barring the fourth impeachment proceeding. There was also no grave abuse of discretion by the House, as it only followed the Constitution and jurisprudence established in Francisco and Gutierrez.

Carpio noted that the Supreme Court’s ruling adds an item for direct exclusion in an impeachment case. It mandates that an official cannot be impeached for acts done prior to assuming the office of an impeachable official. This could include treason or other serious crimes, he said.

“The Constitution does not say that you cannot be impeached for acts done before. It does not prohibit. It does not also allow. It’s silent,” he said.

Amendments to Article XI

This inclusion and the new due process requirements “in effect” are amendments to Article XI of the Constitution on the accountability of public officials, which covers the impeachment provisions, Carpio said.

“If you know that it’s not in the Constitution and then you put it there, you are amending it. I mean, anybody can see that,” he said.

Carpio also said that if for some reason the tribunal does not reverse its ruling on the impeachment of Duterte and retains these changes or amendments, Filipinos will just have to accept that because “the Supreme Court is supreme.” 

“The Supreme Court is supreme not because it is infallible but because its decision is final,” he said. “So, the question is: How do we correct this? The correction is: We just have to amend the Constitution.”

But it is Congress that can propose or make amendments, not the Supreme Court.

Carpio acknowledged that the new requirement for an impeachment and other changes in Article XI can still be pushed or even enshrined in a revised Charter. But he is not optimistic that it will happen.

“Well, I don’t think the House will enshrine it because that will castrate their power. I don’t think the Senate will enshrine it because no impeachment complaint will reach the Senate,” he said.