The concept goes back to the 1978 review by Mary, now Baroness Warnock. Her report ushered in a revolution under the 1981 Education Act, which said that where possible special needs pupils should be taught in mainstream schools with legal statements ensuring they got the right support.
But there was no new money, a decision that sowed the seeds for conflict. Parents and their support groups embraced the statement as their one means of legally guaranteeing pupils the right support.
But the growth in those needs meant that it became a financial time bomb for local authorities. By 2002 the Audit Commission found that 68 per cent of special needs resources were focused on a statementing system that was "costly and bureaucratic", which could divert specialist staff from schools with little scope for wider preventative work. By 2005 Baroness Warnock called for a review of statementing which she admitted was causing "bad blood" between parents and schools.
The Commons education select committee inquiry concluded in 2006 that the Warnock framework was not fit for purpose. There was a "postcode lottery" as different solutions were adopted by local councils. The proportion of pupils with statements varied massively: for instance, Nottinghamshire had 1.08 per cent, while Halton in Cheshire had 4.83. The MPs called for the Government to give clear guidance.
Their report also called for an end to the "inbuilt conflict of interest" caused by local authorities having to assess children's needs and then arranging provision within a limited budget.
It was echoed this week by the Conservative party's SEN policy commission (see box, above left).
The Government has ruled out a "completely fresh look" at the system. And that could be because it had already been encouraging a quiet revolution in the statementing system. The huge number of authorities now delegating statementing funds straight to schools has gone largely unnoticed, perhaps because it is harder to understand than special school closures.
The change has had profound effects, as is illustrated by the drop in new statements, from 36,180 in 1998 to just 22,600 in 2006.
The Department for Children, Schools and Families says it does not keep a list of which authorities are delegating their funding. But it is aware. It encouraged it in 2001 guidance and 2004 SEN strategy.
Roger Inman, chief executive of the Independent Panel for Special Education Advice, a charity, said the policy means local authorities are "psychologically washing their hands" of special needs pupils. If that is so, it has been done with the Government's blessing.