Updated 12.35pm
State and Church school educators plan to go on strike on November 27 in a pay dispute between the union and the government.
The Malta Union of Teachers said that as well as the walk out later this month, teachers will be issued a series of directives on Monday.
Union chief Marco Bonnici said the action followed two "insulting" financial packages.
The government said it had offered "substantial and sustainable conditions" but was willing to continue negotiations.
Strike action will impact primary, secondary and sixth form schools run by the state or the Church.
Junior College, which is run by the University of Malta, will not be affected.
Bonnici did not provide details about the directives aimed at impacting school operations, saying they will be communicated to MUT's members later on Friday.
Government 'broke its word'
He said the action was being called as the government had failed to keep its electoral promise to substantially improve the working conditions of educators.
“If the government chooses to break its word and does not recognise and sustain the work of educators, it will find the MUT with unprecedented actions to safeguard the work of educators,” he told a press conference.
When MUT refused both government proposals, the government cancelled subsequent meetings, the MUT president said.
Negotiations for a new collective agreement began in December 2022.
Bonnici urged educators - including teachers, Learning Support Assistants, heads of school, assistant heads, education officers, heads of departments, and kindergarden educators - to follow the directives.
“The time for waiting is over. All educators must use their voice through industrial action and support the MUT in this issue. It will determine the future of the education sector”.
Bonnici said poor salaries will fail to attract new educators and will at the same time lead to educators leaving the sector for better-paid jobs.
In a statement, the Union of Professional Educators acknowledged the MUT strike and said it was "deliberating the course of action for its members".
'Unfair on students'
Reacting to MUT's announcement, the government said it was willing to continue negotiations and had scheduled a reconciliatory meeting for Monday.
The Education Ministry said it had already tabled "substantial and sustainable conditions that will improve educators conditions".
It added that the directives were not appropriate and were unfair on students and their families.
The last time teachers went on strike in Malta was during the pandemic in January 2021 in a row over online lessons.