Hayley Powers, whose two children go to St Mary Magdalene CofE Primary School, Islington, argued the move would weaken the rights of parents and pupils.

In March, the independent schools adjudicator approved the closure of the school, to be replaced by a London Diocesan Board-sponsored academy.

Judge Mr Justice Wilkie ruled that this decision had not been unlawful.

After the ruling, lawyers issued a statement on behalf of Mrs Powers expressing her disappointment over the result.

'Vindication of academies'

Education Secretary Alan Johnson said the judgement was a "victory for parents who want a better education for their children" and a "vindication of academies".

"The judgement confirms that the government is right to proceed with academies to give children the chance of a good education rather than accept a status quo which let down too many," he said.

"It also confirms that the school adjudicator was quite right to decide that the rights and safeguards provided by an academy's funding agreement are perfectly adequate."

Governors set out plans in February last year to replace St Mary Magdalene with an academy.

Liberal Democrat education spokeswoman Sarah Teather MP said: "Parents will still have serious questions about the government's academies programme.

"Ministers should halt the scheme and take stock about whether it really offers value for money."

Earlier this month, a father won the first round of a legal challenge to plans to close his son's maintained school with a view to it being converted into a sponsored academy.

Rob MacDonald, from south London, was given permission by the High Court to seek a judicial review of Merton Borough Council's decision to close his son's school, Tamworth Manor, and another school, Mitcham Vale.

Academies are independent state schools with outside sponsors who put up about a tenth of the cost of conversion in return for control of the school's governing body.

Sponsors are a mix of wealthy individuals, companies, education organisations and faith groups.