The NSW Teachers Federation has announced its members will strike next Wednesday, May 4 over pay and conditions.
The union's state executive unanimously decided to proceed with the strike at a meeting today.
They have also authorised members to walk off school grounds if a NSW government MP enters them, and have put an immediate ban on the implementation of new policies.
The federation's president Angelo Gavrielatos said there was "no alternative" but to take industrial action.
"If we don't pay teachers what they are worth, we won't get the teachers we need," he said.
"Acting on uncompetitive salaries and unsustainable workloads is the only way to stop more teachers leaving and attract the people into the profession we need to fix the shortages.
"The profession is now left with no alternative but to act in the interest of our students and our profession, and take industrial action."
The federation said that in a poll of 10,000 teachers released today, 90 per cent said they were not paid enough and 73 per cent said their workload was unmanageable.
NSW Premier Dominic Perrottet acknowledged the concerns of teachers but said the decision to go on strike was disappointing.
"They have a right to be frustrated, it's been a very disruptive two years for our parents and for our students," he said.
"That's why it's disappointing that they're choosing to strike.
"I've made it very clear that we'll work through these issues and we'll get a good outcome on the other side."
The strike comes amid an ongoing dispute with the NSW government over public-service wage caps.
Mr Perrottet said he was aware of cost of living pressures on public servants but said he wanted to address the issue of wage increases across the entire public sector.
"There are unique issues with the unions across the board and I want to deal with them all together," he said.
"I'm not going to choose one area of the public service against another.
"We know whether it's a nurse, a paramedic, a police officer, a teacher they all do amazing work in looking after people right across our state.
"We're working in good faith, sometimes change doesn't occur overnight, there are complex issues at hand, I want to have a system that works for everybody."
Teachers went on a state-wide strike in December last year.
