MANILA — Nearly all House representatives from Mindanao have signed a manifesto rejecting the proposal floated by former President Rodrigo Duterte to separate Mindanao from the Philippines, Lanao del Norte 1st District Rep. Mohamad Khalid Dimaporo told a press conference Wednesday.

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"Our stance is deeply rooted in our belief in national unity, the power of inclusive development, and the promise of a peaceful, progressive future for all Filipinos, including the indigenous people of Mindanao," the manifesto against secession said.

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There is no mechanism in the 1987 Constitution, which defines the national territory of the Philippines, for regions to secede from the republic.

Dimaporo said 53 out of the 60 congressmen of Mindanao have rejected the secession of Mindanao earlier floated by Duterte and by Davao del Norter Rep. Pantaleon Alvarez.

"We are one with our President that we don't need to move backwards to the time of darkness in the region of Mindanao," Dimaporo said.

President Ferdinand Marcos, Jr. has called the movement a "travesty" to the constitution, saying also that it is doomed to fail.

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Dimaporo urged local executives of Mindanao to come out and state their stand on the secession call.

"I hope this call for an independent Mindanao will quite frankly be shut down by all 4 corners — all levels of the government — of our leaders in the Mindanao region," Dimaporo said.

"I think the 19th Congress — it's very clear that we will not support a movement for an independent Mindanao," he added.

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The manifesto also urges the prosecution of those sowing disunity.

Alvarez earlier said they were mobilizing a "peaceful and orderly advocacy campaign" for Mindanao "independence", contrary to claims that what they were doing was "seditious."