The Tonga government says claims by Public Services International it is threatening and repressing public servants are completely unfounded.
The PSI wrote to the Minister for Justice, Clive Edwards, saying it supports the Tonga Public Services Association in its fight for a cost of living adjustment, and admonishes the government for threatening workers.
But Mr Edwards says the PSI is misguided and should have checked its facts.
"Their accusations or allegations that they are making are totally without any foundation, any factual foundation, and I'm surprised that an international organisation can make such an accusation without first checking the facts."
Clive Edwards says the PSA's general secretary, Mele Amanaki, is politically motivated as she is contesting his electorate in November's general election.
He says his ministry supports a pay rise for government workers.