De La Salle: Some teachers will no longer co-operate with school's principal
Some teachers at Belfast's De La Salle College have said they will no longer co-operate with the school's principal.
In a letter seen by the BBC, the Irish National Teachers Organisation (INTO), said their members had a "lack of trust and confidence in the leadership of the school".
Members of INTO previously voted for industrial action "up to and including strike action".
The school, in the Andersonstown area of west Belfast, has 1,100 pupils.
There are around 70 teaching staff at the school.
In the letter, to the chair of the board of governors, Ms Monica Culbert, INTO's Northern Secretary, Gerry Murphy, outlined what form the action would take.
The action sanctioned by the union "is one of non-co-operation or engagement with Ms Claire White, principal," it said.
"With effect from 8am on Monday 25 April 2016 all INTO members are directed not to:
- Undertake any instruction or advice given by Ms Claire White, Principal, either in oral, written or electronic form
- Not to attend any meeting...which she has requested or is in attendance at
- Not to undertake any teaching roles if (she)...is present or enters the classroom
- Not to provide any information or data pertaining to their teaching or managerial responsibilities to Ms Claire White, Principal."
More than 50 of the teaching staff in the school are INTO members.
The letter has also been copied to the Council for Catholic Maintained Schools (CCMS).
In a statement CCMS said they were "aware that INTO has confirmed the nature of its industrial action following its recent ballot of members."
"CCMS will continue to work closely with the trade unions and the school authorities in continuing to implement the strategy plan and to ensure that any action will not impact on the education of the pupils."
Ms White has not issued a response to the INTO letter, but previously said the school was focused on the "education provision and emotional wellbeing" of students.
"I would like to pay tribute to my teaching colleagues here at De La Salle College who I thank for their dedication and commitment," she said.
"I will continue, with the wider strategy group, to work towards a mutual resolution."
Meanwhile, the NASUWT which represents a number of teachers in the school, have said they want to ensure stability ahead of the exam season.
"While the union continues to be involved in daily talks with a view to resolution of the on-going industrial dispute, preserving high quality education is our primary focus," an NASUWT spokesperson said.
About a third of the teaching staff were off sick for a period before Easter.
The CCMS subsequently appointed an associate principal to work alongside the principal and senior management.
There have also been a number of meetings over the past few weeks between the Concerned Parents of De La Salle group, which represents some parents, CCMS, politicians and the Education Minister John O'Dowd to discuss the situation at the school.