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

Speculation has arisen that the ICC may issue arrest warrants for Senators Ronald “Bato” dela Rosa and Bong Go, named as “co-perpetrators” of former president Rodrigo Duterte in crimes against humanity tied to the latter’s anti-drug war.

“In my opinion, a sitting senator cannot be arrested within the Senate’s grounds, whether in session or not in session. This had been the 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 said.

Previously, Senate President Tito Sotto and Senator Risa Hontiveros stated that senators cannot be arrested during a Senate session.

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

This immunity covers only minor offenses punishable by six years or less, so Congress members are not completely shielded from arrest.

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

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

Dela 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 the 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 during Duterte’s watch, before the country’s exit, asserting that the preliminary probe had already commenced even before the country departed the treaty.

The ICC document dated 13 February said that Duterte and his co-perpetrators shared a “common plan” to “neutralize” alleged criminals, including those suspected of illegal drug use, through “violent crimes, including murder.”