A Muslim free school in Derby has been told it must take action to stop discriminating against women and girls or face closure.
In a letter sent to the Al-Madinah Free School on Monday, Schools Minister Lord Nash also said the school had failed to "keep pupils safe" and provide a good education.
Al-Madinah School, which is run by the Al-Madinah Education Trust, has been told it must provide evidence within the next week that it has stopped any practices that lead to women and girls being treated "less favourably" than men and boys.
It also has to notify all staff that they are not required to cover their hair if it is against their religion or beliefs.
A number of reports last week revealed that female teachers at the school were "forced" to wear hijabs even if they were not Muslim whilst girl pupils were made to sit at the back of the classroom and boys at the front.
In his letter, Lord Nash said: "The Trust has manifestly breached the conditions of its funding agreement by failing to ensure the safety of children at the school; delivering an unacceptably poor standard of education; discriminating in its policies and procedures towards female staff; and failing to discharge its duties and responsibilities in respect of the governing body.
"I will not tolerate breaches of the commitments you gave when entering into the funding agreement."
"Unless swift action is taken to address these concerns in a comprehensive way I will be compelled to terminate the school's funding agreement," he warned.
On Tuesday the school website declared it had now re-opened after "fully addressing the urgent Health and Safety issues that emerged following an inspection by education authorities."
The school's founding headteacher Andrew Cutts-Mckay left after less than a year in post.
He was quoted as saying, before the school opened, that it would "honour all faiths" and would have 50% non-Muslim pupils.
In a statement, Ofsted chief inspector Sir Michael Wilshaw said the school re-opened after inspectors made a return visit to ensure that the right checks - such as criminal records checks - were in place.
"Ofsted began an inspection of Al-Madinah School on Tuesday October 1," Sir Michael said.
"On the same day, the principal took the decision to close the school as a result of inspection concerns over safeguarding checks. Inspectors discovered that staff records showing whether they were cleared to supervise children were either missing or incomplete.
"The school remained closed until yesterday when inspectors made a return visit to satisfy themselves that the necessary safeguarding arrangements were in place and that there were sufficient numbers of adults with the necessary clearance for the school to function safely.
"In particular, inspectors needed to see evidence that CRB/DBS checks had been properly completed for employees and were held on an accurate, single central register."BLOG COMMENTS POWERED BY DISQUS