Incumbent senators cannot be arrested within the Senate premises, regardless of whether Congress is in session, Senator Win Gatchalian said Tuesday.

This follows speculations of a looming warrant from the International Criminal Court against Senators Bato de la Rosa and Bong Go, who were recently named as “co-perpetrators” of former president Rodrigo Duterte on crimes against humanity tied to his bloody anti-drug campaign.

“In my opinion, a sitting senator cannot be arrested within the Senate’s grounds, whether in session or not in session. This had been a practice before,” Gatchalian said partly in Filipino in a radio interview.

The Senate, he added, is an “independent institution” that has its own rules and procedures, which law enforcement groups are bound to “respect.”

“We have already seen this in many, many instances in the past,” he concluded.

Previously, Senate President Tito Sotto and Senator Risa Hontiveros also expressed a similar position that no senators could be arrested while the Senate is in session.

Article VI, Section 11 of the 1987 Constitution prohibits a senator or member of the House of Representatives from being arrested while Congress is in session.

However, it applies only to minor crimes or offenses that carry six years or less in prison. This indicates that members of Congress are not completely immune from arrest.

In March last year, De la Rosa announced plans to use the Senate as a “hideout” to evade arrest from the ICC over his role as the architect of Duterte’s war on drugs, which killed thousands, mostly from poor communities.

This mirrored past actions by former senators Leila de Lima and Antonio Trillanes IV, who also sought refuge in the Senate to delay or avoid arrest for their drug-related and rebellion cases, respectively.

De la Rosa and Go are both staunch allies of Duterte, having served as his former Philippine National Police chief and top aide, respectively. Their bond dates back to Duterte’s stint as Davao City mayor from 1988 to 2016.

The two senators have long criticized Duterte’s arrest on 11 March at Ninoy Aquino International Airport on an ICC warrant coursed through Interpol and executed by local police, citing the Philippines’ withdrawal from the Rome Statute—the tribunal’s founding treaty—in 2019.

The ICC, however, insisted on retaining jurisdiction over the alleged crimes against humanity that were committed under Duterte’s watch, prior to the country’s exit, asserting that the preliminary probe had already commenced even before the Philippines departed the treaty.

An ICC document dated 13 February showed that Duterte and his co-perpetrators shared a “common plan” to “neutralize” alleged criminals, including those suspected of illegal drug use in the Philippines through “violent crimes, including murder.” The scheme was implemented during Duterte's tenure as Davao City mayor and later expanded nationwide after he won the presidency in 2016.

Aside from De la Rosa and Go, also named as Duterte’s co-perpetrators are former Justice Secretary Vitaliano Aguirre II, the former president’s ex-lawyer in cases involving the so-called “Davao Death Squad,” and De la Rosa’s successor, former PNP chief Oscar Albayalde.

Others include Vicente Danao and Isidro Lapeña, former Davao City Police chiefs; Camilo Cascolan, finance chief of the Davao Region Police Office; Dante Gierran, Davao regional director of the National Bureau of Investigation; and other unnamed high-ranking law enforcement officers.

De la Rosa, who has been absent from the Senate since November following reports of an impending ICC warrant, remained mum on the recent ICC document tagging him as one of Duterte’s co-perpetrators.

Go, on the other hand, denied involvement in the killings, branding the ICC’s allegation as “entirely unfounded, one-sided, unfair, and bears no relation” to his previous roles under Duterte’s tenure as Davao City mayor and as Philippine president.