The families claim that Government proposals threaten the legal right to special provision. They believe that the proposals will weaken the law leaving special needs children at the mercy of schools and local education authorities and relying on goodwill.
There are also fears that quotas will be introduced cutting the number of children with statements.
The children released green and white balloons representing the thousands of young people who would be affected by the proposals.
The event followed a meeting where campaigners spoke out against the plans. Conservative MP Angela Browning, who has a son with special needs, said she had sought assurances from ministers that children would not lose the right to the education that their statements say they need.
David Phillips, whose son has special needs and has sought a judicial review against his local authority, said he saw a local authority memo regarding his child which referred to the least the authority "could get away with".
He said: "Desperate parents with children with special needs are among the most vulnerable in society. Local authorities are blatantly ignoring codes of practice."
A survey by Coopers amp; Lybrand last year found the number of statements had risen by 40 per cent in the past five years. Three per cent of pupils now have statements compared to the 2 per cent envisaged by the Warnock Report, whose recommendations led to the 1981 Education Act.