Following its two-hour rolling work stoppages last week, the University of South Australia staff union announced on Monday that a new round of four-hour work stoppages would be observed starting Tuesday morning.

The National Tertiary Education Union (NTEU) said that the latest protest actions would be implemented by union members on all campuses of the university, including Whyalla and Gambier, as they continue their campaign for higher pay and better working environments.

NTEU branch president Kevin Rouse said that part of their demands was to discontinue the university's practice of offering casual contracts to hired staff as he added that further protest actions would erupt if the school administration refused to budge and negotiate with them.

Mr Rouse called on the university authorities to meet the union members at the bargaining table and possibly agree to some concessions, which should follow up on earlier deals made on salary demands and collective bargaining agreement.

The NTEU admitted that some classes would be disrupted and cancelled once staff commence their protests and walk away from their duties, which Mr Rouse characterised as an unfortunate but necessary consequence of their actions.

He cited that regular classes, lectures and tutorials were disrupted last week with the two-hour stoppage and more cancellations should occur once the protest actions start rolling on Tuesday.

On his part, Professor Gerry Griffin, the university's chief of negotiators, lamented that the union had to launch the planned protests as he downplayed their possible effects on the school's regular classes.

Professor Griffin said that the union's actions would not a help a bit in securing their demands from the university, stressing that "the university would have preferred continuing on the bargaining process to resolve the issue as all disputes are ultimately resolved through negotiations and conciliation and this dispute will be no different."