South Korean Foreign Ministry has slammed the Democratic Party (DP) for sending an official letter to the Pacific Islands Forum (PIF) to ask them to work with the party to oppose Japan’s planned release of its treated nuclear water into the sea.

“The Democratic Party’s delivery of this letter disregards the joint efforts of the international community, including with the International Atomic Energy Agency, as well as our own safety assessment efforts, and is not helpful for an objective verification process,” said the ministry in a statement on Sunday.

“In addition, the ministry finds the action regrettable because it does not respect the inherent authority of the executive branch,” the ministry added, referring to its designated role in diplomacy.

The Democratic Party had forewarned earlier last week that it will send a letter to the members of the Pacific Islands Forum. It wasn’t immediately clear when its letter was submitted to the forum.

Some members of the conservative People Power Party called it a usurpation of power.

“It’s terrible evidence of the fact that the Democratic Party is even willing to sacrifice national interest for its party interests,” said Yun Jae-ok, floor leader of the People Power Party in a party meeting at the Assembly on Friday.