MANILA (Reuters) - Philippine President Rodrigo Duterte on Tuesday withdrew amnesty for an opposition senator involved in a failed coup 15 years ago and ordered his arrest, in what would be the second detention of a lawmaker critical of him.

Antonio Trillanes, Duterte’s most vocal opponent, has accused him of hiding wealth, and has supported petitions to the International Criminal Court (ICC) seeking his indictment over the alleged murders of thousands of suspected criminals and drug dealers.

An executive order printed in the pro-Duterte Manila Times newspaper said clemency for the former military serviceman had been voided because he fell short of the minimum requirements, including admitting his guilt.

In 2010, then President Benigno Aquino gave Trillanes amnesty for involvement in a failed 2003 coup and a mutiny four years later, both aimed at overthrowing then-President Gloria Macapagal Arroyo, a Duterte ally.

Trillanes called the executive order “stupid” and said he would not resist arrest or flee.

“It’s a clear case of political persecution,” he told reporters. “Mr. Duterte is a dictator. He does not respect institutions. That is why we’re like this: ordinary people are killed and critics are jailed.”

Trillanes is the latest of Duterte’s detractors to be targeted, accused of offences opponents call trumped up or technicalities.

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They include politicians, lawyers, a reporter, a judge, a United Nations rapporteur and even an elderly nun and a campaigner for indigenous peoples’ rights.

‘MAXIMUM TOLERANCE’

Duterte, now on an official visit to Israel, has long maintained he has never penalized anyone for criticizing him.

Presidential spokesman Harry Roque said Duterte had proven his “maximum tolerance for freedom of expression” and was simply enforcing the law by voiding an amnesty awarded as a political favor.

“It never was effective, there was nothing to undo,” Roque told reporters in Jerusalem.

“He (Trillanes) did not ask for amnesty, it was given to him on a silver platter.”

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Trillanes’ arrest would make him the second of a vocal Senate minority to be detained after Leila de Lima, a former justice secretary held for 18 months charged with involvement in illicit narcotics.

Both have targeted Duterte over his bloody war on drugs and have led Senate enquiries into his role in alleged executions by police, both while president and when a city mayor. Duterte denies wrongdoing.

The ICC in February started a preliminary examination of a complaint that accuses Duterte of crimes against humanity.

Legislative immunity did not cover Trillanes because of the seriousness of the alleged offences, which included rebellion and sedition, said Justice Secretary Menardo Guevarra, adding that invalidating the amnesty was not a political move.

“This is not to scare anyone, but to ensure all of the laws are followed and obeyed,” he told reporters.

Senator Risa Hontiveros said the action signaled “Duterte’s further slide into full authoritarian rule”.