The Caledonia Together Party says the President Harold Martin has become the first New Caledonian leader to attack a political party at an international forum.
The party issued a statement after Mr Martin told the UN Decolonisation Committee in New York last week that the Caledonia Together Party's electoral success was based on its stance on what flag should be used.
It says the President has alleged that it wanted to create trouble because it calls for New Caledonia to choose only one flag.
The Caledonia Together Party says his address should have been used to speak on behalf of the entire collegial government, leaving internal issues aside.
It says an honourable politician represent his country with dignity and doesn't besmirch its name.
The Caledonia Together Party says it wonders whether Mr Martin spoke on behalf of his own party or on behalf of those politicians who lost out in this year's election success to the Caledonia Together Party.