Eight Catholic schools in the region will also be stopping work, including James Sheahan Catholic High School, Catherine Mcauley Primary School and St Mary's School at Orange, and Assumption Primary School at Bathurst.

Independent Education Union (IEU) General Secretary John Quessy said St John's Catholic College staff would be wearing red and assembling against the insulting and disrespectful proposal made by Catholic employers.

"The current employer proposals would lead to larger classes, less time for lesson preparation and less resources in the classroom," Mr Quessy said.

"They are also demonstrating their desire to protect the quality of teaching and learning that they provide in schools. They have built this capacity which is now being threatened by the employer proposal."

IEU organiser Jackie Groom said it was hoped the intervention would force employers to negotiate around current salaries and conditions rather than those contained in their draconian proposal.

Last month, St John's College staff voted overwhelmingly to take industrial action against the proposed agreement.

Of the 50 teachers who voted in the St John's ballot, 48 were in favour of "an unlimited number of stoppages of work for part of an hour, or one or more part hours", while 47 voted yes for "an unlimited number of stoppages of one or more half days in duration."

St John's Primary School participated in a postall vote, however insufficient ballots were returned on time for the industrial action to occur.