School managers are set to meet with the association of secondary school teachers on Monday as the row over supervision and substitution threatens further disruption.
The ASTI is instructing its members to implement the scheme on the basis that they will be paid for being on call, as well as for carrying out their duties.
The Minister for Education Noel Dempsey says that arrangement is not acceptable and he wants the union to clarify its position by Monday.
School managers say the ASTI proposal would make the scheme difficult to operate.