A study ranking the education performance of local authorities and academy chains reveals that the lowest performing school provider at both key stage 2 and 4 is a MAT.

But the results also show that the highest performing school providers at key stage 2 and key stage 4 are also MATs.

The research has been produced by thinktank the Education Policy Institute (EPI) - formerly known as Centre Forum - to allow a comparison of both local authority maintained schools and academies.

The study shows that the Education Fellowship Trust, a chain with eight primaries in Northamptonshire, is the worst performing school provider at key stage 2. Pupils at the trust make one term’s less progress than average.

However, the top-performing provider in the country at key stage 2 is the Harris Federation, where pupils make a term and half more progress than average.

A similar story emerges at key stage 4, where the Stoke-on-Trent-based College Academies Trust is named as the worst provider in the country for GCSEs, while the best performing provider is the Inspiration Trust.

The Norwich-based MAT made improvements equivalent to their pupils achieving one grade higher in 4 GCSEs compared with the national average.

The thinktank said its research shows that government should focus less on types of school, but whether children are attending good schools or not.

David Laws, former Liberal Democrat schools minister and chair of the EPI, said the government should instead be focusing their efforts “like a laser” on underperformance.

“If I had this information when I was in the DfE I would have been spending a lot of my time prioritising these underperforming schools. We have seen over the last 15 years that focusing on underperformance and changing leadership in these schools can generate success,” he said.

The thinktank recommends:

• The government abandons full academisation as a policy objective;
• Interventions should not favour local authorities or MATs, but target underperformance;
• the government considers allowing high-performing local authorities to become MATs.

The study coincides with a separate report by the Sutton Trust, which showed one in five established sponsored academy chains are performing “substantially below” the national average for attainment and improvement for disadvantaged pupils.

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