The Caledonia Together Party says it is strongly against plans by the Melanesian Spearhead Group to invite Fiji's interim prime minister, Commodore Frank Bainimarama, to Noumea in July.
New Caledonia's pro-independence FLNKS Movement is an MSG member and is to host its next summit.
The Caledonia Together leader, Philippe Gomes, and the territory's outgoing member of the French senate, Simon Loueckhote, say there is no call to host the region's only dictator.
They say they have decided to write to the French foreign ministry in a bid to stop his visit while an MSG delegation looks at the implementation of the Noumea Accord.
The New Caledonian politicians also say they objected last month to Roch Wamytan attending the MSG summit in Fiji in his capacity as New Caledonia's Congress president and thereby supporting the Fiji regime.
Mr Gomes says the planned visit by the Fiji regime leader also goes against the position taken by the Pacific Islands Forum, Australia and New Zealand.