The government has been urged to review its policy on multi-academy trusts after it was revealed that more than 40,000 children were being educated in “zombie schools” waiting to be transferred to another academy chain.

Department for Education figures, obtained through a freedom of information request, show 64 academy schools are waiting to find a new sponsor after being abandoned by, or stripped from, the trust originally managing them. A calculation using the average number of pupils in state-funded primary and secondary schools in England – 279 and 946, respectively –suggests the 64 schools would contain more than 40,000 students.

The government has encouraged academies to join multi-academy trusts, promoting them as a support for schools that have left local authority control, although some have been criticised for financial mismanagement and a lack of oversight.

Half of the 64 “zombie schools” are waiting to be transferred from two chains: the Education Fellowship Trust and Wakefield City Academies Trust. In March the former became the first trust in England to give up control of its 12 academies – including a school in the prime minister’s Maidenhead constituency – following concerns about educational standards. In September the Wakefield trust said it would divest itself of 21 schools across Yorkshire, as it could not undertake the “rapid improvement our academies need”.

The DfE said it was in the process of securing new academy chains for the schools in both trusts.

Until a new multi-academy trust is found, the schools remain in limbo, often unable to make long-term planning decisions, hire new permanent members of staff or organise pay rises. They do not have the option to return to local authority control. Campaigners say that the government is struggling to find new chains willing and able to take on the schools, many of which have been left in a precarious financial position by their previous sponsor.

“The Tories’ fragmented education system is now creating ‘zombie schools’ caught between academy chains who are under no obligation to take them on, and a government that won’t step in to help them,” said Angela Rayner, Labour’s shadow education secretary. “Even in the prime minister’s own seat it seems there are classrooms of children not getting the education they deserve.”

The figures come after it was announced on Thursday that Bright Tribe academy trust would let go of Whitehaven academy in Cumbria following complaints by teachers, parents and pupils that the school was in a dilapidated state. Of its decision to relinquish the school, which it took over in January 2014, Bright Tribe said: “As we have been unable to grow beyond a single school in Cumbria, we recognise the need to explore alternative sponsor options for Whitehaven academy.”

In October the issue of failed academy chains received renewed focus when it was revealed that the Wakefield trust had transferred millions of pounds of its schools’ reserves to its own centralised accounts before announcing, days into the new term, that new sponsors would need to be found.

In November 2016 a leaked draft of a report by the DfE’s Education Funding Agency said the trust was in an “extremely vulnerable position as a result of inadequate governance, leadership and overall financial management”. Rayner has called on the government to say what it knew of the trust’s financial position before its collapse.

Last week Wakefield city council backed a motion asking that the trust be allowed to return to local authority control, arguing that the police should investigate the trust’s finances. Councillors said the trust should not be permitted to dissolve until an investigation had taken place and the results made public.

“This scandal could happen again if we don’t learn the lessons,” said Rayner. “The Tories have abandoned proper oversight of schools, and we now have a system that is fragmented and unaccountable.”

The Tories rejected Labour’s proposed amendments to the Education Act in 2015 that would have given Ofsted the power to conduct full inspections of trusts as well as their schools.

National Education Union activist Sally Kincaid, who has worked closely with WCAT schools, said the schools were unable to make steps to improve themselves while they were waiting for a new sponsor. “In one sense, the kids are still going to school and the teachers are still teaching them, but you can’t move anything forward because the mechanisms by which you do that aren’t there. So, for example, the staff won’t know if they’ve got their 1% pay rise this year because there’s no one there to make that sort of decision.”

The DfE said: “Academy trusts operate under a strict system of oversight and accountability, and in any instances of underperformance we will not hesitate to take swift action, including transferring schools to new trusts when necessary.” It said that, in 2016-17, 165 of 6,500 academies were “rebrokered”.