One in five primary schools is expected to fail minimum standards in English and maths by 2016 because of a “perfect storm” of challenges including the changing curriculum and a swath of experienced headteachers approaching retirement, a think-tank has warned.

Policy Exchange, a right-leaning research group that has helped shape the Conservatives’ education policies, says this threat could be warded off if all primary schools in England were forced to convert into academies and local authorities were encouraged to set up their own academy chains.

In a report published on Tuesday, researchers endorse the government’s introduction of tougher floor targets, but estimate that 3,000 primaries will not meet these standards over the next two years. The think-tank blames a combination of stresses on the school system including the Department for Education’s reformed curriculum and new assessment mechanisms, as well as the gradual decline in support from local authorities.

Compounding these problems, 21 per cent of primary school heads are approaching retirement age and the School Teachers Pay Body has raised concerns about replacements, the report says.

It concludes that the reorganisation of all primary schools into academy chains by 2020 is “the only viable opportunity” for schools to “mitigate against the risk of mass failure”. While 55 per cent of secondary schools already function as academies – which receive state funding but are independent from local authority control – only 11 per cent of primary schools have chosen to operate autonomously.

Jonathan Simons, head of education at Policy Exchange, admitted that academy status was “not some sort of panacea which will automatically lead to improvements”, but said grouping schools into academy chains was a way of encouraging collaboration and sharing of best practice.

“Bringing schools together in academy chains is what is needed [to avoid failure],” he said. “And while there are some already moving in this direction, simply leaving it up to individual schools risks being too slow.”

Sir David Carter, the regional schools commissioner for southwest England who also wrote a foreword to the report, added that the approach to primary education needed “fundamental change”.

“We simply cannot meet ambitious new goals, compete and beat our international competitors, and lay the foundation for the world class outcomes . . . by simply working harder within the framework of the current system,” Sir David said.

But Tristram Hunt, Labour’s shadow education secretary, suggested the best way to improve standards was to employ a “world-class teacher in every classroom”.

“That means scrapping David Cameron’s unqualified teacher policy that has produced a 16 per cent increase in the number of unqualified teachers in our schools,” Mr Hunt said.

Nansi Ellis, assistant general secretary of the Association of Teachers and Lecturers, criticised the plan to force primary schools to become academies, and blamed the coalition’s “massive changes” for the problems schools are facing.

“The government needs to focus on ensuring there are enough teachers and on the quality of their training, rather than wasting time and money turning schools into academies and free schools,” Ms Ellis said.

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