Pupil-teacher ratios have risen since 2010 because student numbers have grown and teacher recruitment has failed to keep up, new figures show.

Research from the Education Policy Institute thinktank lays bare the severity of England’s teacher recruitment crisis, with just one in five physics teachers holding a relevant degree in some parts of the country.

According to the EPI’s analysis, pupil numbers have risen by around 10 per cent since 2010, while teacher numbers have remained steady.

This has resulted in pupil-to-teacher ratios increasing from around 15.5 in 2010 to nearly 17 in 2018.

Teacher training applications were down by around 5 per cent compared with the same time in 2017, with training targets persistently missed in maths and science.

Teacher exit rates have crept up, with only 60 per cent of teachers working in a state-funded school in England five years after starting training. For high-priority subjects like physics and maths, the figure is even lower, at 50 per cent.

There is considerable variation across different subjects in the proportion of teachers who hold a degree which is categorised by the Department for Education as "relevant" to what they teach. In biology, where there is less pressure on recruitment and retention, 78 per cent of teachers hold a relevant degree, but the proportion falls to less than 50 per cent for maths and physics.

Shortages 'most severe in deprived areas'

The EPI report reveals stark differences in how likely a teacher is to hold a relevant degree in the most and least deprived schools in the country, with the socioeconomic gap greatest outside London.

Teacher shortages are most severe in physics. In the worst-off schools outside of London, fewer than one in five physics teachers (17 per cent) have a degree in a relevant subject. In more affluent schools outside of London, the figure rises to just over half (52 per cent).

In the capital there is a much greater proportion of physics teachers holding a relevant degree – with between 40-50 per cent holding one, regardless of school deprivation level.

To tackle teacher shortages, the EPI recommends introducing a government-funded national salary supplement scheme for subjects such as maths and science.

David Laws, executive chairman of the EPI, said: “This report demonstrates that the government faces a significant challenge to recruit enough teachers – particularly in subjects such as maths and sciences.

“It must already be a concern that as little as half of GCSE maths teachers don’t have a maths or sciences degree.”

He added: “We need to make it more attractive for some of our best qualified teachers to teach in our most challenging schools.”

Commenting on the EPI report on teacher shortages, Geoff Barton, general secretary of the Association of School and College Leaders, said: “The EPI is right that schools are facing severe difficulties in recruiting and retaining teachers, and that schools in areas of high disadvantage often experience the greatest difficulties.

"But we don’t agree with its suggestion of paying salary supplements to teachers in selected subjects, such as maths and science, as it would mean other teachers were paid less than their colleagues despite having similarly demanding workloads and responsibilities.

"This would be unfair and demoralising, and would damage recruitment and retention in subjects which did not benefit from salary supplements. Instead, we would like to see a better deal for teachers in general.

“The government should at least give all teachers the 3.5 per cent pay award recommended by the pay review body this year, rather than leaving many with below-inflation increases. We must also do more to tackle teacher workload, and we need a coordinated national strategy to boost recruitment and retention, particularly in areas of high disadvantage.”