Philip Hunter, the chief schools adjudicator, who also decides which new schools get the go-head, told council leaders that they had nothing to fear from the spread of academies.

His comments were made in a wide-ranging speech to the inaugural Association of Directors of Children’s Services conference in Manchester. He said that he rejected the idea that a faith school ethos could raise standards and warned that falling rolls and grammar schools did not mix.

Mr Hunter said that academies were not like grant maintained schools, which had been given preferential funding. Local authorities should ignore the technicalities and work with them in the same way they would with any other local school, he said.

“If I were Secretary of State I would make them all [state secondaries] academies,” he said.

His office is responsible for ruling on school admissions disputes and decides which new schools get the go-head in cases where there is a conflict of interest with the local authority. His office has turned down two academy plans in favour of a community school run by Haringey Council in north London.

The adjudicator called into the question the future of his own office, telling the conference there were too many official bodies receiving complaints from parents about schools.

Mr Hunter said he got irritated when people such as David Blunkett, the former education secretary, claimed there was something intrinsically good about faith schools. But he had also seen no evidence that they were worse than other schools in using admissions to cream off the most able pupils.

Mr Hunter told his audience that they could do more to fulfil local authorities’ new role of reducing social segregation in schools.

“If you do your jobs well, you can heal some of the divisions in society,” he said.

Last week, his office backed Brighton Council’s plan for a catchment area and lottery admissions system, which the authority argued would increase opportunities for deprived pupils to attend a popular secondary.

On grammar schools Mr Hunter said: “Falling rolls and selection don’t mix.” As secondary pupil numbers drop, grammars had two options. One was to reduce their entry requirements. “We already have grammar schools taking up to 40 per cent of the population so it is not clear whether they are grammar schools any longer,” he said.

John Freeman, ADCS joint president, said: “Academies are now part of the local landscape and we welcome their greater involvement within the community of schools.”