Teachers and support staff in Victorian Catholic schools will rally at school gates and workplaces across the state on Friday as part of an escalating campaign for fair bargaining rights, better pay and improved working conditions.

Galen Catholic College teacher and Union Rep for the Galen IEU sub-branch, Jordi Wells, said they will be continuing to campaign on the Day of Action by wearing black on Fridays as a visible symbol that this fight is far from over.

"It is a reminder that staff remain united in standing up for fair bargaining, manageable workloads and respect for the profession," she said.

"Members do not want conflict, but they do want fairness.

"The Day of Action is a necessary step in pushing employers back to genuine negotiations.

"Every action members take sends a clear message: Catholic school employees deserve fair bargaining rights and an agreement that reflects the work they do every day."

Independent Education Union Victoria Tasmania said its members will hold a statewide Day of Action on Friday, 29 May, with staff wearing union colours, gathering before and after school, and speaking publicly about growing workload pressures and the need for a fair agreement.

The union said unlike staff in the government sector, Victorian Catholic school staff are currently unable to take protected industrial action because Catholic education employers have refused to agree to fair multi-employer bargaining arrangements - a refusal the IEU is challenging in the Fair Work Commission, with hearings due to begin in June.

The union says unresolved issues include salaries, workload protections, time in lieu, camp allowances, paid parental leave, education support classifications and basic union rights.