AN anomaly in the method used to calculate teachers’ working time is forcing some part-timers to take on extra work to make ends meet.

Gill Hargreaves, 37, a part-time primary teacher in Liverpool, has to spend three hours washing dishes at an hourly rate of pound;3.80 every Saturday morning so that she can qualify for family credit, which pays for childcare while she is teaching.

Although Mrs Hargreaves works for two-and-a-half days a week, Liverpool education authority calculates her working time as 13 and three-quarter hours, the time she actually spends in front of a class. But to claim family credit, worth around pound;60 a week, Mrs Hargreaves has to work at least 16 hours a week. Her husband cannot claim because he is a supply teacher and his hours fluctuate.

Mrs Hargreaves had to quit her full-time teaching post after the birth of her third child, who suffers from a chronic illness.

“It is very unfair,” said Mrs Hargreaves, who attends staff meetings and parents’ evenings, marks work and prepares lessons just the same as any full-time teacher. “It discriminates against part-time teachers who are parents.”

Some LEAs, such as neighbouring Sefton, include marking and preparation time. Mrs Hargreaves’ union, the NASUWT, has told her that she cannot take her case to an equal opportunities tribunal because of a local agreement between Liverpool education authority and the teaching unions that a full-time teacher’s working week should count as 27 hours.

The Teachers’ Pay and Conditions Document does not specify how working time and pay rates should be calculated, according to a spokeswoman for the Association of Teachers and Lecturers. Hourly rates can vary between 11,268th of an annual salary to 1900th, although many local education authorities pay 1195th of a full-time salary per day.

A spokesman for Liverpool education authority this week said that the Benefits Agency should take account of the hours teachers work outside the classroom. “The agreement on working hours in Liverpool is generous as it requires teachers to work fewer hours than the statutory requirement of 1,265 a year,” he added.