MALACAÑANG said Friday that the arrest of Senator Leila de Lima, who is facing drug charges, was not politically motivated.

"It's a criminal case filed against her; it’s not a political case, which was filed against her," Executive Secretary Salvador Medialdea said in an interview, after the ceremony of the 31st anniversary of the Edsa People Power Revolution in Camp Aguinaldo in Quezon City.

Medialdea's remark came on the heels of the joint statement of De Lima's allies, expressing opposition on her immediate arrest over her alleged involvement in the illicit drug sale in the New Bilibid Prison when she was Justice Secretary.

De Lima was arrested Friday after a Muntinlupa court found merit in criminal cases filed against her. She will be detained at the Philippine National Police Custodial Center in Camp Crame, Quezon City.

Liberal Party senators Franklin Drilon, Paolo Benigno Aquino IV, and Francis Pangilinan condemned Thursday the "political persecution" of De Lima, which they called as the "brave critic" of the current administration.

"This arrest is purely political vendetta and has no place in justice system that upholds the rule of law. This is condemnable," the senators said. "An arrest based on trumped-up charges is illegal."

Chief Presidential Legal Counsel Salvador Panelo said De Lima is not a political prisoner because there is basis for arrest order against her.

Panelo said the senator's arrest should be deemed as welcoming development as it is proof that democracy is working in the country.

"The arrest of Senator De Lima shows that the law is enforced regardless of who is the subject of arrest, whether the person is holding a high position in the government or has an ordinary status in society," Panelo said.

"The majesty of the law shines triumphantly when as senator of a Republic is arrested and detained on account of a criminal charge. Such is the working of a democracy," he added.

Presidential Spokesperson Ernesto Abella said De Lima would still have the opportunity to defend herself and prove her evidence.

Abella also assured that she "will be treated with fairness and accorded due process."

"The court has established probable cause therefore, let us keep our faith in the judicial system. The moral arc is long but it always bends towards justice. More so, Senator Leila De Lima has nothing to fear in her place of detention," he said.

On Thursday, Muntinlupa RTC Branch 204 Judge Juanita Guerrero ordered the arrest of De lima and co-accused former driver Ronnie Dayan and former Bureau of Correction director Rafael Ragos. (SunStar Philippines)