Catholic school teachers in Tasmania are warning 24-hour strikes could be next after a first ever stop-work meeting over workplace conditions.
Schools in the state's north were forced to run on a skeleton staff as teachers walked off the job for four hours on Tuesday.
Similar action will also hit Hobart and northwest schools this week after negotiations over a new enterprise agreement broke down more than a month ago.
Independent Education Union members have voted to back 24-hour stoppages, and assistant state secretary Angela Briant says that action could be next in the state's 37 Catholic schools.
"That is certainly an option open to us if we need to do that," Ms Briant told AAP.
"But we're hoping this week that the Catholic education employers hear the message loud and clear.
"We will go further if we have to because we've got to maintain the faith of our members.
"We can't let them down."
Talks have dragged on for 18 months with the last agreement expiring in December 2012.
The union says teacher support staff should be employed for a guaranteed 40 weeks per year, home room time should be included in teaching loads and redundancy entitlements are being eroded.
They say their claims are on par with government school teachers' conditions.
"You're sending a message you don't really value them," Ms Briant said.
"We're happy to go back to the table and talk again if they have a better offer."
Catholic Education Office director Trish Hindmarsh has said some of the claims are unreasonable and industrial action is an over-reaction.
Dr Hindmarsh said schools would remain open during this week's stoppages.
"It is our intention to have our schools as fully functioning and focused on learning programs as possible," she said in a statement.