Tonga's Public Service Association has applied to the Supreme Court for an injunction to stop government from implementing a new salary structure.
Matangi Tonga reported the application filed this week was the PSA's latest attempt to stop government saying the new structure was unfair.
The PSA had also said there was not enough consultation leading up to the changes.
Since 2012 the government's Remuneration Authority has been working on the new civil service structure.
On June 29 the PSA petitioned government to defer the introduction of the new salary structure to next year but that was rejected.
In July the association petitioned King Tupou VI for the same reasons and they are still awaiting a response from the Palace Office.
The PSA claims that it has the support of civil servants however the Remuneration Authority has said it doesn't reflect the views of the entire service.
The association has called a halt until all members' grievances are addressed.