Academies are switching sponsors at an increasing rate – with at least 54 schools changing hands since 2012, Schools Week can reveal.

Figures obtained via a Freedom of Information request reveal that 26 individual academies changed sponsor last year, compared to just three in 2012. And in the first four months of this year, 21 schools transferred ownership, with 11 switching on April 1 – the last day possible before the general election.

Some observers are concerned, however, about the disruption and uncertainty that so many changes could cause to pupils, staff and parents.

Nansi Ellis, assistant general secretary of policy for the Association of Teachers and Lecturers suggested these switches could negate government promises of putting ownership into the hands of parents and committees.

She added: “There is also a lack of transparency in the academy process that will be made worse by increasing changes of sponsorship – particularly if those changes are negotiated privately between sponsors and government.”

Academies have moved between sponsors for a variety of reasons, such as underperformance, geographical isolation and partnership consolidation. Moves have required some schools to change names, bring in new head teachers, new uniforms or a change in curriculum.

Academy trust E-Act has released the highest number of schools, giving up 10 in the last year. The Department for Education had urged handovers in February last year amidst criticisms that several of E-Act’s schools were underperforming.

The Academies Enterprise Trust (AET) – the largest academy chain in the country – also relinquished control of eight schools, as reported by Schools Week in April. The trust was barred from taking over any more schools, following suggestions it had been expanding too fast.

Of the schools handed off from AET, three were taken on by Leigh Academies Trust, where Frank Green, the government’s schools commissioner in charge of the entire academy project, is a director. He was also chief executive of the trust before resigning in February last year.

Two Coventry primary schools, Ernesford Grange Community Academy and Radford Primary Academy, also changed their sponsor just eight months after converting. Sidney Stringer Academy, an Ofsted-rated outstanding secondary school and sixth form in Coventry, took both schools on in January last year.

The total cost of changing sponsors is also unknown. Previous attempts by a campaigner to discover this information, using freedom of information laws, were rebuffed due to “commercial sensitivity”.

At present, individual academies cannot simply leave a trust. Only the trust itself can choose to “release” a school. The disparity was raised by the education select committee’s report into academies, which recommended a rule change so that good and outstanding schools could leave by choice.

New government legislation means schools requiring improvement could be forced to find an academy sponsor.

Robert Hill, a former government education policy advisor and visiting senior research fellow at King’s College London, told Schools Week there was a risk of more change if large numbers of struggling schools were suddenly made into academies.

However he noted there are many more approved sponsors today – about 700 in total – who were available to work with the schools. “But Regional Schools Commissioners will still need to beware of, as it were, overloading strong academy trusts and giving them a school improvement workload they will struggle to meet,” he said.

A DfE spokesperson said: “Academy sponsors are key to making sure every child has a chance to go to a good or outstanding local school. We have been clear that we will act decisively where schools are underperforming.

“We work closely with schools throughout the conversion process to ensure that any disruption to pupils’ education is kept to an absolute minimum.”