During a recent Prime Minister’s Questions, Jeremy Corbyn asked why 70 per cent of headteachers are now using agency staff and why we spent £1.3 billion last year on supply teachers.

“Are we not moving to an era that we could term ‘Agency Britain?’” he wondered.

It’s true: increasing numbers are now leaving to work for private agencies who profit from ploughing the same staff back through the system at additional cost to schools. 

That teachers leave their posts only to return, effectively as contractors, free of micromanagement and buckling workload, tells us much about what teachers value and how we can redress the retention crisis.

No financial benefit

For supply staff, money is certainly not the incentive: most will forgo their teacher’s pension rights, holiday and sick pay. Moreover, with the decline of local authority supply pools, which pay staff to scale, for many teachers a large percentage of a payment goes not to them (some earn just £80 a day) but to agencies for whom business is booming.

Teachers, some of whom are recruited at source from university, are sometimes forced away from PAYE and told they must register as employees of an umbrella company for purposes of payroll. Many don’t understand the implications of such middlemen until they open their payslip and find they are paying both employer and employee’s NI, plus a commission charge.

After 12 weeks, as per agency workers’ regulations, teachers are allowed to escape a flat “daily rate” and become salaried. But research from the NASUWT teaching union found that 42 per cent of supply teachers were not paid commensurate with experience. 

Buying back our teachers wastes public money. This is particularly concerning at a time when a study of Association of School and College Leaders members finds that the combination of recruitment issues and funding cuts is having a damaging impact on the provision of education, further pressuring staff remaining in post.

If we cannot afford supply teachers, school leaders will be placed in the invidious position of asking support staff to do the work of agency teachers, a trend justly highlighted last week by Mary Bousted.

The only way to break this cycle is to reflect on the increasing attraction of supply work and commit to making permanent posts desirable again and, crucially, to recognise that while many still enjoy teaching, they don’t enjoy being a teacher.

A popular TES article is “I can be happy - or I can be a teacher.”: to end the recruitment crisis, we must make sure supply isn’t the only way that it’s possible to be both.

Anna Kalinski is a writer and teacher and can be found on Twitter @annakalinski.

TES Global, parent company of TES, owns two teacher supply agencies: Vision for Education and Smart Teachers ​