The NSW Teachers Federation President Angelo Gavrielatos said next Tuesday's strike "will be the first 24 hour stoppage in a decade".

"Over the course of the last 18 months we have exhausted all options available to us to arrive at a negotiated settlement with the government," he said.

"They won't budge from a one-size-fits- all 2.5 per cent wages cap despite their own education department's warning that teacher shortages exist because other careers pay more competitive salaries."

Mr Gavrielatos said the strike was voted on unanimously in Saturday morning's federation meeting in Sydney.

The strike comes on the back of NSW-wide federation rallies throughout November. According to Mr Gavrielatos "teachers and principals are seeking a salary increase of between 5 to 7.5 per cent a year" and "an increase in preparation time of two hours a week" in order to attract and retain teachers.

"The Perrottet Government doesn't seem to care that the shortages are so bad that one in five teachers are teaching outside their subject area," he said.

"If you don't care about teacher shortages, you don't care about kids missing out."

IN OTHER NEWS:

A NSW Education spokesperson told the Newcastle Herald the department is "disappointed" in the plans to inconvenience "students and families who have already experienced a difficult year".

"The Department has notified a dispute in the NSW Industrial Relations Commission (IRC) and is seeking orders to prevent the NSW Teachers Federation's from proceeding," the spokesperson said.

The department has made an application for an interim salary increase of 2.5%, the spokesperson said, until the teaching award is arbitrated by the IRC in May.

NSW Minister for Education Sarah Mitchell described claims by the federation that the state is heading for a teaching crisis as "blatantly misleading and self-serving".

"The union has refused to negotiate or engage in an award negotiation for teachers, leaving them without any pay rise at all," she said.

"In the union's absence, the government is applying to increase pay for teachers by the maximum amount so staff do not miss out this January."