The Tonga Public Service Association says it's important that a proposed new employment relations law deals first with basic rights for workers, and worker benefits can be negotiated later.
The government has extended public submissions for the draft bill to the end of the month.
The secretary general for the Public Service Association, Mele Amanaki, says the union wants controversial issues such as holiday and sick leave and the minimum wage left out of the bill for now.
She says it's more important to have basic rights for workers in place.
"This bill is not only about the benefits of the employees. It is also about regulating the employers not to fire the workers as and when they want. Because that's what's currently happening now. Sometimes there is discrimination in recruitment because you are a woman, or because you are a foreigner, because you are from the outer islands, those are important things that needs to be regulated and implemented now."
Mele Amanaki says her union also supports the bills proposal to register trade unions.