There has been some support from parent groups, but the teachers union says the policy will increase safety risks for staff and students by constraining teachers' ability to manage disruptive and dangerous behaviour.

NSW Secondary Principals Council deputy president Denise Lofts said the new Inclusive, Engaging and Respectful school policy sounded good in theory but wouldn't work in schools for a number of reasons.

"It is not a universal approach to managing young people. It needs to be good for all kids, even those doing the wrong thing," Mrs Lofts said.

"There are rights of the individual. There are also rights of the critical mass. We need to be mindful of keeping everyone safe.

"Secondly any new change needs to be resourced adequately. We are critically under-resourced and overworked as it is.

"It is really interesting that schools at this point in time need so much more because we've got kids that are really traumatised from the last two years.

"I know everyone is saying suspensions are going up, and they are....but suspensions are going up because we have really traumatised kids sitting in our schools and if we don't have the resources to help them then society is going to be the real loser in the end."

A Department of Education spokesperson said student suspension rates remained disproportionately high for NSW public school students, particularly for students with a disability and Aboriginal students, as well as those in rural and remote areas, in out of home care, or experiencing socioeconomic disadvantage.

The new strategy aimed to halve the length of school suspensions. Principals may only suspend a student more than three times in a calendar year if staff or student health and safety is placed at risk with approval of their Director Educational Leadership.

Mrs Lofts, who has been an educator for 35 years, including as Ulladulla High School principal on NSW's South Coast, for the past 13 years, said it upset her when people assumed principals took delight in suspending students.

"As a principal, the hardest thing we do in our job is a suspension for a young person," she said.

"I have 12 support classes and I have to suspend kids with disabilities but it is our last resort. We've done everything else prior to that, even making sure that they are fed probably.

"We have a policy that I think works well in schools and is procedurally fair for all kids. It respects all kids. It is no good if you can't suspend a kid or you can't help a kid at the detriment of every other kid. That is the problem, it's about the critical mass."

IN OTHER NEWS:

The Department spokesperson said the new Inclusive, Engaging and Respectful schools policy "isn't just about reducing suspension - it's about genuine early intervention and prevention to stop challenging behaviours from occurring in the first place. If we can achieve this all students will benefit.

"Unfortunately the union has directed its members to not engage with the process and they are actively spreading misinformation about the policy to the detriment of students. Thankfully other stakeholders are engaging, and with their help the policy and implementation approach has changed to better suit the workforce.

"This new approach will also give principals, teachers and staff access to evidence-based support, including allied health and behaviour support services, to allow them to put in place early intervention and prevention measures. Providing more support to our staff will mean students are supported to remain in school through positive behaviour, and reduce the days lost through suspensions."

Mrs Lofts argued principals and those who worked in schools knew best if the new policy was the best way to go forward.

"I think a lot of the times the policy seems to sit apart from what really needs to happen in schools," she said.

"It needs to be an authentic piece of policy that is vested in the schools.

"If you want good policy you have got to go where the people have the knowledge and the wisdom. And, the wisdom that sits in schools I think has not been used to inform a direction going forward."

The implementation of the Inclusive Engaging and Respectful Schools package is to be staggered throughout 2022, to allow more time for schools to engage with the new policies and additional support for implementation.