Correspondence about teaching assistants has highlighted the important role that they play in schools and their low pay (Letters, September 18). But it has not mentioned the fact that a majority of low-paid support staff undertake substantial amounts of unpaid overtime, and that many schools rely on this “goodwill” to function effectively.

This has been highlighted in recent research for the DCSF that we led at London Metropolitan University. We found that many teaching assistants and administrative staff reported working more than their contractual hours.

TAs were often paid only for the hours during which children were in class. However, in order to do their jobs, they also needed to work outside these hours.

The reasons that they gave for this generally related directly to workforce remodelling. For example, TAs who took classes during teachers’ PPA (planning, preparation and assessment) time pointed out that they needed time to plan or prepare too, and only two in five had such time allocated on their timetables.

Some explained that they worked on lesson plans in the evenings; others said that they had to work unpaid during their lunch hour or after school, preparing the classroom and resources, and tidying up.

A recent Institute of Education report also found that unpaid overtime was common among support staff. Both studies show that teachers benefit substantially from the work of support staff, which enables them to focus on teaching, and has contributed to a reduction in stress. It is clearly unacceptable if this improvement in conditions for teachers results from support staff “goodwill”, arising from their loyalty to the schools and commitment to pupils.

Professor Merryn Hutchings, Ayo Mansaray, Dr Uvanney Maylor Sarah Minty, Institute for Policy Studies in Education, London Metropolitan University.