Rhona Mackenzie, of the Scottish recruitment team, said the reduction to 23.5 hours should force a change of thinking in primary classrooms. Other staff would have to come in and take classes, leaving teachers extra time for planning and correction.
They should be able to sign out when they had done their time and deserved the same rights as secondary colleagues.
Mrs Mackenzie, however, appealed to primaries not to run classes of less than 45 minutes with other specialists. It left no time for class teachers and little room for development among the specialists.
Linda Gray, West Lothian, said specialists should have "realistic time blocks" and secondary staff would be expected to make their skills available in primary.