The evidence that there are not enough teachers in schools - and that this situation is only going to get worse - is mounting.

Exclusive research by Tes showed that England needs 47,000 more secondary teachers by 2024 if it is to cope with over half a million more pupils transferring from primary to secondary schools as the bulge in pupil numbers goes through the education system. 

This overall shortfall, according to Tes, presents an enormous challenge in some subjects. In modern foreign languages, nearly a quarter of all graduates with a 2:2 degree would need to train as teachers each year.

In maths, the figure is an astronomical, and frankly unachievable - 40 per cent of graduates choosing to become teachers.

This is a problem that secondary school teachers in shortage subjects will recognise. It is a tale of woe told to me often. These teachers tell me that, in addition to their own excessive workload, they are supporting colleagues in their department who are teaching out of their subject area. 

As one said to me last week: ”I am working a 70-hour week supporting two colleagues who don’t have the subject knowledge to teach maths at GCSE level - particularly with the new GCSE syllabuses, which have added masses of more difficult content.”

Teachers forced to teach outside their subject area

Another senior leader wrote to me this week with similar concerns: ”This year, in order to ‘help out’ with a gap in the timetable, I am teaching A-level computer science.

“It’s a new specification. The textbook, which we bought before the course started, is adequate but has very limited practice material. There’s a more recent publication which is much better, but we can only afford one copy per class to share. So I have joined the ranks of teachers having to create my own resources and photocopy pages from books we’d rather buy.

“We have just begun final exam preparation. There is one published specimen paper from the exam board. We used that as a ‘mock’ a few weeks ago. There is no other repository of relevant questions.

“Yesterday, I spent two hours combing through past papers from a different exam board. I identified which questions are on the new specification as best as I could. I created a booklet of material. I don’t mind doing it: it’s relatively enjoyable! I could try and make up my own questions, but many of them involve diagrams that are not easy to recreate using standard software. Two hours’ preparation for a one-hour lesson.

”... There are about 2 million students sitting new examinations this summer (GCSE, AS, A2) - that’s about 100,000 classes. If each student is doing five subjects and each class teacher has spent 10 hours on resource generation (that could have been provided by the examination boards), that’s 5 million additional workload hours.”

These lived tales of teachers are borne out by research published this week by the Education Policy Institute (EPI), ”The teacher labour market: a perilous path”.  The EPI research shows that a very high proportion of teachers are teaching out of their degree subject in certain EBacc subjects.

Foreign languages hit by teacher shortage

Modern foreign languages are particularly badly affected in this regard. In German, only 55 per cent of teachers have a relevant degree qualification; for French, it’s 53 per cent and for Spanish, it’s an alarming 35 per cent.

Just over half (51 per cent) of physics teachers hold a relevant degree qualification. Even more alarmingly, under half (46 per cent) of maths teachers have a maths degree.

These figures are bad, whatever government gloss is put upon them. They provide evidence of just how parlous is the state of teacher supply.

What is even worse, however, is that the Department for Education does not take into account the percentage of teachers teaching out of their subject area. As the EPI researchers note: “This means that in subjects where recruitment targets are persistently missed, e.g. physics, there is still someone in front of the class, but they are increasingly a non-specialist in that subject. This is concerning if you think that non-specialists cannot provide the same quality of education as specialists.’

Searching questions must be asked about the wisdom of this government in its headlong rush to introduce the revised qualifications at GCSE, AS and A level when there are neither the teachers nor the curriculum resource materials to ensure successful delivery of the new qualifications.

And in the end, of course, it is the pupils who suffer when the building blocks for successful teaching and learning are not put in place before major curriculum and qualification change. 

All the ministerial guff about a rich, knowledge-based curriculum will come to naught if there are insufficient teachers, and inadequate resources, to teach this curriculum.

In its recent report ”Retaining and Developing the School Workforce”, the Public Accounts Committee accused the DfE of “failing to get a grip” on teacher retention. 

On current evidence, the government’s grip on this crucial issue is weakening further. Perhaps the best that can be hoped for is a ministerial finger in the wind?

Mary Bousted is joint general secretary of the NEU teaching union. She tweets @MaryBoustedNEU