The Interim-Public Service Association in Tonga says a nearly three-week long strike over wages is changing to a political protest.
Thousands of workers have called for wage increases of up to 80 percent.
The government has previously offered increases of up to 30 percent and suggested an independent auditor be called in to look at the wage system.
The interim-PSA secretary, Vuna Fa'otusia, says the government's response has been unsatisfactory and caused more frustration.
"Now one of the banners says that, Stay focused, 80, 70, 60..fair distribution for all. That banner may change next week to something like, Stay focused. Sack the government!"
The interim-PSA secretary in Tonga, Vuna Fa'otusia.