The court ruling could result in nearly 1,000 sacked officials seeking their jobs back.

One of Aquino’s first steps when he assumed office on June 30 was to dismiss hundreds of officials, who he said had been illegally appointed by former President Gloria Macapagal Arroyo when her government was operating as a caretaker this year.

This week, the Supreme Court ruled that a dismissed official should be reinstated, a decision Aquino said tested the limits of the courts’ constitutional power and could lead others who had “been replaced, resigned, or recalled” to seek their jobs back.

“The potential result of this will be chaos and paralysis in the executive branch of government, as the legitimacy of officials appointed to replace those already removed will be cast in doubt,” he told a news conference.

Eduardo de Mesa, Aquino’s legal adviser, told Reuters the ruling could see nearly 1,000 officials demanding reinstatement.

“That ruling could open the flood gates of similar petitions from officials that we have removed, creating chaos in the entire bureaucracy,” de Mesa said, adding the government would appeal.

Aquino, who had opposed the appointment of an ally of Arroyo as chief justice a week after the May presidential elections, said the decision “could precipitate a clash with another separate, co-equal branch of government.”

Last month, the high court, where 14 of 15 judges were appointed by Arroyo, stopped the lower house of Congress from starting an impeachment process against the head of the anti-corruption agency, an Arroyo ally.

Aquino said his government had kept silent on that decision, but he was worried the latest ruling could have an impact on his efforts to restore public confidence.

“We have saved the Filipino people billions of pesos by rescinding contracts that have been uncovered after the midnight appointees have been removed from office,” Aquino said.

“The economy is on an upturn. This order can set back all of these achievements.”