The minister of family affairs in French Polynesia, Tina Cross, says she will no longer use French in the assembly.
This comes after the French supreme court ruled last week that Tahitian wasn't to be used during assembly debates.
The ruling followed a case brought by the former French high commissioner in Papeete, Michel Mathieu, who wanted only French spoken.
Mrs Cross says the constitution makes French the official language but she says to ban Tahitian is racist.
"They don't have to forbid us to speak our native language. From now I speak only the Tahitian language because to make them realise it is a very colonialist and discriminatory law that they did. I will no more speak French."
Tina Cross says it is now deemed to be illegal if anyone speaks Tahitian in court or parliament and it will not be recorded or recognised.