Tamworth's Catholic school teachers walked off the job on Friday in their first 24-hour strike in 18 years.
Independent Education Union organiser David Towson said 23 schools in the Armidale diocese had struck in order to pressure the state government to drop its public service pay cap.
The Catholic school system has tied the wages of its teachers to state schools for 30 years, so the government needs to change its policy to shift their pay, he said.
"No-one takes industrial action likely," he said.
"Our members are forgoing their day's pay, but they've got to a point where the situation is critical and they need to take action."
The union wants a pay rise of between 10 per cent and 15 per cent over two years, in line with anticipated inflation. The state has offered just 2.04 per cent.
About 100 teachers from Catholic schools from as far as Armidale to Quirindi gathered in Tamworth to hold a stop work meeting on Friday.
The unionists had one simple message for the government: "2.04 - teachers walking out the door".
They're also looking for a pay bump for support staff.
Aboriginal education assistant Kim Taggart told ACM she's paid significantly less than she would be if she worked in the public education system, which "isn't fair" and "isn't Catholic".
"It honestly makes me feel disheartened that we're in the same role and I'm not being acknowledged," she said.
"I'm hoping that [the diocese] realise the inequities between the Catholic system and the public system and realise there is quite a large inequity, and match it. They're losing staff, they're losing support staff."
The industrial action was given a significant boost, after winning a degree of support from Director of Schools Chris Smythe, from the Armidale Catholic Schools Office.
"Teachers and support staff deserve a meaningful pay increase and whilst the strike is a huge inconvenience for staff and a disruption for students and parents, I strongly believe we need to stand up for the status of the teaching profession," Mr Smyth said.
Independent Education Union sub-branch president Libby Lockwood said teachers simply need a pay rise.
"The working conditions of our school staff are the learning conditions of our students," she said.
Mr Towson said there was a major shortage of teachers and the union was simply aiming to defend the profession.
"There's a situation where McCarthy up the road will have more than 20 teachers away on any given day," he said.
"Similar to O'Connor over in Armidale, and there are no casual teachers to fill the gaps."
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