At the last minute, with legal action looming and schools about to break up for the summer, ministers decided to withdraw the proposed rule changes, due for September.

The new rules, set out in a revised SEN code of practice, would have meant that local authorities would no longer “normally” have to say how much help a child should receive.

Instead, they would have to spell out support only “where necessary”.

The Independent Panel for Special Education and Advice (IPSEA) threatened legal action. It said the rule change would give authorities an excuse not to set out how much support a child should receive, and many children’s needs would not be met.

The bid was criticised by Opposition MPs in the Commons last Tuesday, and the issue was to be debated in the Lords. But before the debate could happen, schools minister Baroness Ashton announced that the proposals had been withdrawn. New guidance will be issued for next January.

John Wright, a spokesman for IPSEA, said: “It was very late in the day, but we very much welcome this courageous move. The Government has acted in the best interests of children.”

John Bangs, assistant secretary of the National Union of Teachers, said:

“We argued that unless LEAs were forced to set out the quantity of provision they would provide, the whole code would be undermined. We’re pleased that it’s been withdrawn.”