The Tonga Public Service Association says schools in the country have beenn badly affected by the redundancies made by the government over the past week.
Nearly a thousand public servants have taken redundancy as the government moves to trim its costs.
But the union has several times raised concerns about how services would be affected.
This week there have been problems with garbage accumulating in the streets of the capital, Nuku'alofa after all the rubbish collectors took redundancy.
And Dr Aivi Puloka of the PSA says they are hearing many complaints about the difficulties posed particularly for primary schools with a number of teachers accepting the redundancy offer.
"This we knew would happen and especially for the teachers because we did ask that we delay in the programme so that we finish the school year. Now there are a lot of transfers between schools to cover up the main core of the functions of the schools, but the teachers are already complaining of the stress that they have to face and having to take more classes and having to attend to more students per class."