POST-PRIMARY principals say they have "grave concern" about the impact of industrial action on schools including fears about safeguarding issues.
In a letter sent to the Education Authority (EA), the Post-Primary Principals Association said it fears "union directives to members to down-tools" means potentially school leaders may have to "close their schools due to lack of staff supervision".
The letter also highlights concerns about recruitment and maintenance of school estates and calls on the EA to show "leadership, guidance and support during this time of real crisis for school leaders".
It comes just weeks after the north's teaching unions announced "unprecedented" joint industrial action after rejecting a two-year pay offer from the employers. The action will affect school meetings, administrative tasks and lesson plans with members instructed to refuse to take on unpaid duties or participate in board of governors' meetings.
But post-primary school principals have raised concerns about the action, particularly fears about members refusal to supervise pupils.
In a letter to the EA, they said "although we remain aware of the ongoing negotiations surrounding a resolution to matters concerning percentage pay increase", they have "grave concern...about union directives to members to 'down-tools' - leading to safeguarding issues and pupils being put at risk within schools".
"It will not be long before principals will be placed in the difficult position of making decisions to close their schools due to lack of staff supervision within schools," the letter states.
The association also states its frustration relating to recruitment suggesting "it is evident that schools are struggling to find suitable applicants for key teaching and non-teaching posts within schools" adding the "amount of time new appointees have to wait for completion of their contracts is alarming".
It also highlights how "maintenance as a service is failing at a systemic level".
A spokesperson for the EA said: "We can confirm we have received a letter from the Post-Primary Principals Association and are currently working on responding directly.
"We are committed to constructive engagement and negotiations with all relevant parties regarding the issues raised."
Justin McCamphill from the NASUWT highlighted that the industrial action had been "endorsed by 98 per cent of members in a formal ballot".
"Teachers wish to avoid industrial action but they have been left with no choice as their employers have failed to make a satisfactory pay offer or tackle their spiralling workloads.
"There has been little recognition of the contractual rights of teachers across many schools, teachers are regularly pressured to supervise and carry out admin duties which take them away from the vocation which they spent years training for.
"Our members are strong and united, and they are saying they will no longer tolerate the damage being done to education and to their working lives."