MANILA – President Rodrigo Duterte on Friday defended his move to amend the Philippine Constitution, amid opposition from some of the prominent framers of the 1987 charter.

The president was responding to the vow of some members of the 1986 Constitutional Commission (Con Com) who vowed to block any attempt to change the charter.

Duterte said, the Constitution needs to be amended for the country to keep up with the times.

“Iyung gumawa ng constitution ni Cory, they (said they) will fight tooth and nail. They will never allow any amendment,” Duterte said in a speech in North Cotabato.

Duterte, however, stressed that he won on a platform of change. He claimed he was the only one among the presidential candidates who brought up the peace problem in Mindanao, which he believes can only be addressed by amending the charter.

“I’ve told you before, right at the start of the campaign, that I’m running because nobody on stage was talking about Mindanao. Kaya ako napasubo tumakbo because whenever they talk in public, they seem to have forgotten that the there is a civil war in Mindanao,” Duterte said.

Duterte has been advocating a shift to federalism, saying this will address inequality. His allies in Congress are now eyeing to convene as a constituent assembly by July this year.

Former Chief Justice Hilario Davide, who was part of the 1986 Con Com, said he plans to block attempts to amend the post-EDSA 1 Constitution.

"I am willing to die for the 1987 Constitution...I would also be willing to die against any moves to amend this constitution," he said.

Former 1986 Con Com member and former Commission on Elections chair Christian Monsod also opposes amending the 1987 charter.

Monsod said the 1987 Constitution "was written as a reflection of the Filipino people's struggle for democracy," and carries the themes of social justice, rejection of authoritarian rule, and that national destiny rests on Filipinos themselves.

He appealed to the Duterte administration to instead push for constitutional reforms instead of a complete overhaul of the charter.

"First, try to reform rather than overhaul the system," he said.

Meanwhile, Edmundo Garcia, also a member of the 1986 Con Com, emphasized the need to protect human rights always.