Tonga's Public Service Association is accusing the Prime Minister Lord Tu'ivakano of not following due process in the appointment of key staff in the Public Service.
It says this affects the PSA's integrity, effectiveness and efficiency.
The PSA has raised concerns that the chairperson of the Public Service Commission, Mishka Tu'ifua, remains in that position even though she is employed full time in another roll in the private sector.
And it questions the continuing employment of 'Aholotu Palu as the acting Chief Secretary and Secretary to Cabinet, when regulations require such posts to be filled permanently within a year.
It says the appointments to both these crucial positions failed to go through the recruitment due process.