Schools are breaking the law by continuing to operate back-door selection policies that discriminate against poor, vulnerable or disabled children, the Government said this week.

Jim Knight, a schools minister, wrote to local authorities yesterday to say he was aware of cases in which schools were illegally breaking the latest admissions code, even though it came into force nearly a year ago.

Their discriminatory tactics included interviewing prospective pupils, using subjective tests and giving priority according to parents’ first school preference.

“There is absolutely no excuse not to comply with the law to stamp out unfair and covert admission practices, which penalise low-income families and increase social segregation,” said Mr Knight.

Philip Hunter, the chief schools adjudicator, said he expected a “splurge” of complaints about schools breaking the code later this year, and that most would comply after that. But he warned the Commons schools committee that even if they did, it would still need further intervention from local politicians to counteract racial and social segregation in some areas.

Ministers’ also want to give disadvantaged parents a fairer deal on school places via “choice advisers”, which they pledged would operate in every local authority by this year.

But this week Sir Bruce Liddington, the Government’s schools commissioner, said councils were not appointing them and data was not collected about how many did.

He told the committee that although he was known as the “choice champion”, a more apt title might be national champion for “expressing a preference”.