CATHOLIC school staff across the Southern Downs may take part in a strike action on Thursday.

Independent Education Union of Australia - Queensland and Northern Territory (IEUA-QNT) said in the Warwick area alone, there were six schools with more than 120 members authorised to take stop-work action.

IEUA-QNT branch secretary Terry Burke said it would be up to Queensland Catholic school employers to decide whether schools would remain open.

Executive director for Diocese of Toowoomba Catholic Schools Dr Patrick Coughlan said school closures were not expected.

"It is unlikely that any Catholic school within Warwick, Stanthorpe, Inglewood and Allora, would be closed as a result of the stop-work action on (Thursday)," he said.

Mr Burke said the campaign over working conditions in the Queensland Catholic schools sector had escalated, with the strike the eighth stop- work since negotiations began 10 months ago.

Dr Coughlan said a wage increase of 2.5% had been offered.

"The current CPI rate is 1.7%, so this offer is fair. The offer applies to all staff across the board. It also comes with a commitment to backpay staff," he said.

"This increase is in line with the interim wage increase provided to Queensland state school teachers in 2015. Additionally we have offered to match any future wage increases.

"Toowoomba Catholic schools employ - in Warwick, Stanthorpe, Inglewood and Allora - 111 teachers with its school officer and support staff being 59. Of these, less than a quarter of the staff voted for industrial action."

Mr Burke said increasing workloads and wage issues were the critical employee concerns.