French Polynesia's ruling Tapura party has come out against the Opposition's Moetai Brotherson, accusing him of staging a media coup over the legacy of the French nuclear weapons tests.
French media quoted a letter by Mr Brotherson in which he asked the French president Emmanuel Macron to arrange the clean-up of the weapons test sites.
He had already asked the French prime minister as well as other key ministers last year to remove irradiated residues from Moruroa, where in excess of 100 tests were conducted.
The Tapura didn't refer to the radiation question but alleged that Mr Brotherson suffered from Stockholm syndrome for raising environmental concerns about the planned Hao fish farm and the proposed phosphate mining on Makatea.
It said he wrongly tied those matters to French colonial rule when in fact the decision-making rests with the French Polynesian government.
Mr Brotherson wrote that France would honour itself if it tackled the nuclear contamination and sent a strong signal to Polynesians, the Pacific and French youth who want strong actions for the environment.