He is therefore “delighted” to have been named chairman of the Church Schools Company (CSCo), which is fast building up a portfolio of these privately-sponsored state schools to match its small group of flourishing independents.

The first, the Lambeth academy in south London, opens this autumn. The Manchester and Northampton academies will open in September next year. Two more may be announced shortly and CSCo’s eventual aim is to have 10.

Lord Carey’s educational salvation came through service in the armed forces, followed by private study to gain the O and A-levels needed for his divinity degree at London University. A masters and doctorate followed.

He sees the city academy, with its marriage between state and private sectors, as a solution to the failure of state education in many inner-city areas. CSCo, founded in 1883, runs eight private schools.

Its initial involvement in the city academy programme arose through an approach from Andrew Adonis of the Downing Street Policy Unit.

Sir Ewan Harper, the charity’s chief executive, told The TES: “I went to Number 10 and was told a city academy had been announced in Lambeth but the corporate sponsor had dropped out.”

Since then, he has met junior education ministers David Miliband and Stephen Twigg, and Education Secretary Charles Clarke. “We’ve been very much encouraged to proceed as quickly as we can,” said Sir Ewan, who also runs the charity’s city academy subsidiary, the United Learning Trust.

The chief brake on progress is money. The charity owns its school buildings but has no income-generating foundation. It has to raise the pound;2 million sponsorship money for each academy mainly from private benefactors.

Even then, things do not always go smoothly. Plans for the trust to turn McEntee, in the London borough of Waltham Forest, into a city academy, foundered on governor opposition to a Christian charity taking over a school with a largely Muslim intake.