Schools in England say they face an acute crisis over retention and recruitment without a significant pay increase, as the country’s biggest teaching union warned of strike action this autumn without an “inflation plus” deal. The threat came as new research shows that every 1% increase in pay gives a 2% boost to graduate recruitment in high-demand disciplines such as science, maths and technology. Trainee recruitment is down by 25,000 compared with last year and experienced teachers are leaving the profession at the fastest rate for more than a decade. The National Education Union, the country’s largest teaching union, sent Nadhim Zahawi, the education secretary, a clear warning that the government should support higher “inflation-plus” pay for teachers or face strikes in the autumn. But Zahawi responded by saying that new teachers will receive above-inflation increases to their starting salaries over the next two years, and hinted that strikes would “risk undoing” progress made by pupils recovering from the pandemic and school closures. The last national teachers’ strike was in 2016, by the NEU’s predecessor the National Union of Teachers. Combined action could lead to the largest joint industrial action since 2011, when the NUT and the Association of Teachers and Lecturers, the NASUWT and the National Association of Head Teachers all struck over pensions. The teaching and school leaders unions argue that the government’s submission to the independent School Teachers Review Body (STRB) last year is obsolete after the sudden leap in the rate of inflation, with the consumer prices index last month reaching 9.1%, the highest for 40 years. The STRB makes recommendations on teachers pay after hearing submissions from the Department for Education (DfE) and the unions, and is expected to report before the end of the school year next month. In its submission in December, Zahawi asked the STRB to raise the starting salaries of new teachers to £30,000 – a Conservative manifesto commitment – over the next two years. But the DfE’s submission had salaries for more experienced teachers and school leaders rising much more slowly, by between 2% and 3%, with all pay increases coming from existing school budgets. The letter to Zahawi from the NEU’s joint general secretaries said that “inflation has increased dramatically” since his STRB submission, while teacher pay has already fallen by a fifth in real terms since 2010, leaving average salaries at their lowest level compared to national average earnings in more than 40 years. “You must respond to the new economic reality of double-digit inflation and the threat this poses to teacher living standards. We call on you to commit to an inflation-plus increase for all teachers. It is not good enough to only propose higher increases for beginner teachers,” the letter stated. “We have to tell you that failing sufficient action by you, in the autumn term, we will consult our members on their willingness to take industrial action. And we will be strongly encouraging them to vote yes. “We can no longer stand by while you run both education and educators into the ground.” In response, Zahawi said: “We have proposed the highest pay awards in a generation for new teachers – 16.7% over the next two years – alongside further pay awards for more experienced teachers and leaders.” The education secretary also reacted to the threat of strikes, saying: “Young people have suffered more disruption to their education than any generation that’s gone before, and it’s the vital work of teachers that is helping them get back on track. “The last thing I – or any parent – want to see is anything that would risk undoing that progress. We will be considering the pay recommendations from the independent pay review body in due course.” The NEU’s letter follows a similar demand from England’s other major teaching union, the NASUWT, which said it would hold a national strike ballot if the government “does not deliver pay restoration for teachers”. New research by the National Foundation for Education Research (NFER) found that the government’s pay offer and incentive schemes were “unlikely to result in an adequate supply of teachers in England in 2022-2025, particularly in science, technology, engineering and maths”, and would fail to recruit enough new teachers in physics and computer science. The study estimates that a 1% increase in the teaching starting salary, above graduate starting salaries outside teaching, would lead to a 2% increase in teacher training applicants, suggesting that an increase in pay could improve recruitment as well as retention. Jack Worth, a co-author of the NFER report, said if teachers’ pay rises continued to lag behind the UK average, maintaining the school workforce would be difficult. “The DfE’s proposal to target higher pay increases at early-career teachers is sensible but our analysis shows the overall financial package is still very likely to leave the sector short of the new teachers it needs,” Worth said. Louise Hatswell of the Association of School and College Leaders said the NFER report was “yet more evidence of the total inadequacy of the government’s pay proposals for teachers”, with its real-terms pay cut for experienced teachers and leaders likely to make retention worse and exacerbate teacher shortages. “The underlying problem is years of government-imposed real-terms pay erosion which has devalued the profession. This must be addressed by a significant improvement to pay in general which reverses this downward trend,” Hatswell said. “It is pretty obvious that it is impossible to raise educational standards if schools cannot recruit the teachers they need.” The government’s survey of the teaching workforce in England showed that 4,000 more teachers quit the profession last year than in the previous year, with just 11% retiring out of the 36,000 who left the state sector. It also found that vacancies were at the highest level since records began in 2010. Secondary school heads say they have struggled to find replacement staff this year, with figures showing a 14% increase in job advertisements this year compared with the period before the pandemic.