The government has ordered the closure of a failing free school for the first time after education inspectors found standards there unacceptably poor.
The Discovery New School in Crawley, West Sussex, has had its funding pulled after failing to make the required improvements.
Schools Minister Lord Nash wrote to governors saying the school must close next April.
The Department for Education said most free schools performed well.
Free schools are state-funded but independently run schools, often set up by parents, teachers and academy chains. There are 174 in England, two of which, including the Crawley school, have been found to be providing inadequate standards of education.
The decision to order the closure of the school will be embarrassing for the government, as free schools are one of its flagship education policies.
But the government insists that overall free schools are providing a good standard of education.
Discovery New School was visited by Ofsted chief inspector Sir Michael Wilshaw's team three times in the past six months.
It went into special measures in May when the education inspectorate warned that children risked leaving the school not being able to read and write.
A monitoring inspection in September judged the action plan of the academy trust that runs the school to be "not fit for purpose".
The latest visit, on 12 November, revealed the academy had not made enough progress to warrant it being removed from special measures. Some 58 "milestones" were to be met by next February.
A DfE spokesman said: "Since the school was placed in special measures by Ofsted in May, we have monitored progress closely.
"The trust has not provided evidence they are making the changes required. Lord Nash has today notified the trust that the department will terminate its funding agreement at the end of the spring term."
The DfE said it was working with the local education authority, West Sussex County Council, to find places at other local schools for the children affected.
It added: "Free schools are held more rigorously to account than any other schools. We have strengthened the criteria and raised the bar for assessments each year.
"Local authorities have presided over schools which have been in special measures for months and done nothing. There are currently 44 local authority schools that have been in special measures for 18 months or longer.
"We have moved to close Discovery New School just seven months after its inadequate Ofsted rating."
Lord Nash, in his letter to the school's chair of governors, Chris Cook, said: "We know from inspection evidence that teaching and learning is inadequate in DNS, and that there has been little or no improvement since Ofsted's judgement that the school required special measures in May.
"The number and nature of the actions and milestones to be achieved demonstrates that the staff are currently unable to deliver teaching and learning even at the most basic level, with the consequence for the pupils of continued inadequate teaching for an unacceptable length of time.
"Further, the training implication for staff is enormous. It is difficult to see how they would be able to attend all the training listed and at the same time provide adequate teaching for the pupils."
'Value for money?'
The move was announced after a National Audit Office report warned that speed in rolling out the programme had been prioritised over value for money. The average capital costs of a free school, many of which are converted from existing buildings, is £6.6m.
Although Discovery New School is the first free school to be ordered to close permanently, the Muslim Al-Madinah Free School in Derby has been threatened with closure if it does not improve. It was also closed temporarily because of health and safety concerns.
On Thursday, an Ofsted report found that there were "no signs of improvement" at the school and that it "remains in chaos".
A statement on Discovery New school's website says staff, governors, parents and children are "deeply disappointed that Lord Nash has refused to give us the opportunity to continue as a free school".
It says the school's improvement plan was "credible and strong" and would deliver change quickly. It argues that the new head had not been given enough time to deliver improvements.
But shadow education secretary Tristram Hunt said: "The closure of this free school is yet another shocking example of why David Cameron's flagship schools policy is failing."
He added that the government had promised that the free schools would bring a rise in education standards we need, but instead, as the NAO reported this week, he said: "It has led to a huge waste of public money and poor standards and now ministers are having to close one down."
"In his terrible rush to roll out the free school programme, David Cameron has abandoned high standards and basic safeguards - and the pupils at the Discovery Free School have paid the price."