More Isle of Man teachers have begun industrial action over a pay dispute.
Members of the National Association of Schoolmasters, Union of Women Teachers are refusing to carry out any duties other than regular teaching lessons.
NASUWT's general secretary Chris Keates said the protest was intended to highlight "activities which are unnecessarily driving up teachers' workloads".
Chief Minister Howard Quayle described the action as "disappointing".
Ms Keates said some duties required of teachers were "diverting them from focussing on their core role of teaching".
The action could affect teachers' lunchtime duties, school sports events, swimming lessons, parents' evenings and study clubs.
Teachers had faced an "erosion of their pay" since 2010, Ms Keates added.
NASUWT backed industrial action in a ballot last month, along with the Association of School and College Leaders (ASCL), and the National Association of Head Teachers (NAHT).
ASCL and NAHT members began similar action on 30 January, and the three unions are continuing the protest indefinitely.
The dispute began in 2018 when the School Teachers' Review Body recommended an across-the-board pay rise of 3.5%, which was instead changed to tiered increases by the UK government.
Pay rises for teachers on the island are linked to those awarded in the UK.
A deal between the DESC and the National Education Union, which would have seen changes to pay including newly-qualified teachers being paid almost £30,000, was rejected by NEU members last month.
Earlier this month Mr Quayle announced an independent review would be held into the pay dispute.