The number of pupils with statements has continued to fall in the past year, despite a sharp rise in the total number of children with special educational needs.
Parents' groups and opposition politicians say the latest figures suggest that vulnerable children are being neglected because of government cost cutting.
But special needs teachers' representatives and the Department for Education and Skills argue that schools are intervening earlier, using delegated funds, so there is less need to go through the statementing process.
The DfES statistics show the number of special needs pupils in English schools rose by 3.8 per cent from 1,473,380 in January 2005 to 1,530,000 in January 2006, despite a fall in the overall numbers on roll.
The figures, released last week, do not show a parallel increase in the number of statements, which specify the extra support cash-strapped local authorities are supposed to provide. Instead the proportion of pupils with statements has remained at 2.9 per cent, while actual numbers fell by 5,830 to 236,750.
Since 1997, when Labour came to power, the number of new statements issued every year has dropped by nearly a third from 35,650 to 24,040. There were nearly 2,000 fewer statements issued in 2005 than in the previous year.
Annette Brooke, the Liberal Democrat children's spokesperson, said:
"Parents will quite rightly want assurances that their children are getting the support they need. The Government is not giving local authorities the resources they need for adequate provision of services.
"It should be a wake-up call to ministers when they see how many children from poorer homes are struggling."
But Lorraine Petersen, chief executive of the National Association for Special Educational Needs which represents staff, said she was not surprised by the fall in statementing. Schools and authorities were finding alternatives, such as employing more teaching assistants.
"The statementing process is very long-winded," said Ms Petersen. "There are more creative ways of supporting these kids."
Alison Carter, joint head of legal services at the Children's Legal Centre, a national charity that advises parents on special needs law, said it was becoming harder to gain statements. As more children were identified with special needs, local authorities were becoming reluctant to issue them.
"It depends on the authority," she said. "But some are very resistant, because of their budgets."
A DfES spokesperson said many councils were delegating more money to schools, allowing them to intervene early to address the needs of pupils more quickly.
"We want parents to have confidence that their children will get a good education and that their needs will be met effectively in school, without feeling that the only way to achieve this is through a statement," the spokesperson said.