Experienced teachers and school leaders in England will continue to endure a decade-long pay freeze if the government’s plans for teacher salaries are adopted, according to the Institute for Fiscal Studies.

The IFS said long-serving teachers and heads will experience a 14% real-terms cut in their pay going back to 2010, following the below-inflation increases proposed by the Department for Education in its submission to the teachers’ pay review board.

The analysis comes as Nadhim Zahawi, the education secretary, is to give a keynote speech to the Association of School and College Leaders annual conference on Friday, in which he is to say that support for teachers will be “at the heart” of the forthcoming schools white paper.

The DfE has asked the School Teachers Review Body (STRB) to recommend substantial increases in pay for newly qualified teachers in state schools, allowing starting salaries to rise from about £25,000 to £30,000 in 2024, meeting a commitment in the Conservative party’s 2019 election manifesto.

But the IFS found the rise will come at the expense of much lower increases for teachers with more than five years in the classroom or in senior roles. Those teachers instead face a real-terms pay cut of 5% over the next two years.

Luke Sibieta, a research fellow at the IFS, said: “Smaller pay rises of 2%-3% per year for most other teachers are likely to represent real-terms cuts and would follow on from more than a decade of real-terms pay cuts. There is also a risk that the highly unstable geopolitical and economic situation pushes inflation higher still.”

The government’s proposals work out to a 4% pay rise if applied across the board. But the IFS said that a higher average pay award of 5% for teachers was affordable this year thanks to the rise in school funding from September.

“An increase in school funding of close to £4bn in 2022 means there is room for a higher pay award within planned school budgets. A higher award than that proposed by the government may carry fewer risks than a lower one,” Sibieta said.

Zahawi will also announce that he is establishing a new arm’s-length body to help teachers and schools design the curriculum and deliver lessons. The new body will repurpose the Oak National Academy, created by a group of teachers and academies to deliver online lessons during the 2020 school closures.

“Instead of each teacher reinventing the wheel, they will be able to access content, for free, that continuously evolves and gets better and better on the back of feedback from teachers across the country – saving time and improving lessons immeasurably,” Zahawi will say.

However, the education secretary will be accused of allowing schools and colleges to be “thrown to the wolves” by his decision to restart league tables based on this year’s exam results.

Pepe Di’Iasio, president of the Association of School and College Leaders and head teacher of a secondary school in Rotherham, will tell members: “How can it be right to compare the performance of one school or college with another when they have been so differently affected by the pandemic over the last two years?”

A survey of ASCL members found that 80% were opposed to league tables being resumed.