The parent company of England’s first for-profit free school has admitted it is providing a sub-standard education to its students.

Internationella Engelska Skolan (IES), the Swedish provider that runs the Suffolk free school IES Breckland, has told TES that it has been forced to stage its own inspection of the state-funded independent, which found that it is “not representative of our schools”.

The company said that it was spurred into making the decision following the departure of its principal, Sherry Zand, who left the school in November last year, and amid general concerns over the quality of teaching.

During the internal review, Ofsted’s own inspectors paid a visit and while their report is yet to be published, IES is not expecting it to be favourable.

It is another blow to education secretary Michael Gove’s free-school policy, which has already seen two schools being forced to close due to concerns around standards, and another being investigated by police over allegations of fraud.

A spokesman for IES told TES: “We inspected our school in Breckland after the former principal stepped down and decided that it wasn’t representative of our schools or our vision of how our schools should be. With this in mind, we set to work to make improvements at the school so that it could provide the education the students deserve.

“This Ofsted inspection came in the middle of a process of change at the school, strengthening the leadership and teaching staff,” the spokesman added.

“This is an ongoing process which sees some upheaval in the short term in order to produce a long-term result. Our impression was that the inspectors perceived that we were already addressing the issues they raised, and we hope that this will be reflected in the report when it is published.”

IES Breckland was one of the country’s flagship free schools when it opened in 2012, and was the first in the country to be run by a for-profit company, after the parent-led trust behind the school entered into a 10-year contract with IES worth £21 million.

The money pays for the entire running of the school, including teachers’ salaries and IES’ management fee.

Alarm bells were initially raised following the departure of a number of teaching staff, and then Ms Zand, who was founding principal of the school, stepped down so she could be closer to her family in Surrey.

Earlier this month it was announced that Alison Tilbrook would take over as the new principal, and IES has said that a number of new teachers had started, with more expected to come in due course.

Upon taking up her new role, Mrs Tilbrook said the school was “crying out for someone who could drive its teaching and learning”.

The National Union of Teachers (NUT) said IES Breckland’s troubles showed that free schools were not the solution to improve standards.

“Clearly, a system where schools are all centralised under the secretary of state is not the right way forward,” NUT general secretary Christine Blower said. “These are young people’s lives that are being affected. Michael Gove needs to start listening - free schools are not the answer to raising educational attainment.”