"We are low paid workers. We've had a pay freeze for two years" says Dave Warren, from the PCS union.
"This year, there's a one percent increase available, which is a joke in itself, but apparently the Government wants to tie that to the loss of our terms and conditions. We find that totally unacceptable."
More top news
All primary and secondary schools in Wales have been categorised in a new colour-coded system. Is your school green or red?
A yellow warning for snow and ice on Thursday night and Friday has been issued.
Some wintry showers and staying windy with a significant wind chill and widespread frost developing