Hundreds of teachers across 17 South Australian Catholic schools will skip meetings, refuse yard duty and are threatening to walk off the job to demand better pay and conditions.

The teachers are continuing to take action after almost 100 staff members from Cardijn College’s Marian campus at Noarlunga Downs were the first to walk off the job on Friday.

Staff at schools including Rostrevor College, Christian Brothers College and St Aloysius College are authorised to miss work meetings, refuse yard duty and skip after school events.

Other schools involved in the pay negotiations include St Paul’s College, St Columba College and St Joseph’s Memorial School at Kensington.

The Independent Education Union SA (IEU SA) is seeking a 6 per cent annual salary increase for three years for teachers and support staff.

Catholic Education South Australia (CESA) has offered 3 per cent increases and a one-off payment of $2200, which it believed was “a fair and genuinely strong offer for our teachers and education support officers”.

It also offered to match pay increases negotiated with public school teachers.

According to CESA, that increase would bring experienced teachers to an annual salary of almost $131,000 by 2028.

Negotiations have been ongoing for more than 18 months and if they continue to stall, IEU SA members are considering a co-ordinated strike involving hundreds of teachers from all 17 schools.

CESA asked the Fair Work Commission to allow all staff to vote on the proposed agreement with a hearing in October to determine whether that will take place before the end of the year.

But the IEU SA argues a vote would result in separate agreements with Catholic organisations including Edmund Rice Education Australia, Mercy Schools Australia and the Catholic Church Endowment Society.

St Paul’s College English, geography and history teacher Sam Dodson said he was “left with no choice but to take action” to campaign for a pay rise to keep up with the cost of living.

“A lack of a pay rise in over two years has made it even harder to save for a deposit (for a house) and enter the market,” the teacher of four years said.

IEU SA branch secretary Tim Oosterbaan said teachers were “looking at a broader stop-work action”, co-ordinated with staff at all 17 schools, as soon as October.

Mr Oosterbaan said his members “wanted the chance to take protected industrial action to get a better offer”.

“Just voting something down doesn’t get a better offer,” he said.

“Make the offer better and we won’t have to take industrial action.”

A CESA spokesman said it was “continuing to negotiate in good faith and will continue to do so”.

“We have made significant progress to date and CESA employers remain committed to promptly negotiating a new agreement so that pay increases and other benefits can be applied,” he said.

“We recognise the importance of pay to our staff as an integral outcome of the bargaining process.”