The judgment will be on whether LEAs have a duty of care under common law for professionals they employ, be they teachers, psychologists or others. If they agree that they do, parents will gain the right to sue the authority for damages if those professionals fail in their duty. The case has been brought by the local authorities after an Appeal Court ruling in April, when Sir Thomas Bingham, Master of the Rolls, said the case for negligence claims over inadequate education was 'not unarguable'.
Few are prepared to estimate how much the decision could cost local authorities, but some families who are already involved hope to receive up to pounds 250,000 and the Lords' decision could open the door to a flood of similar claims. One support group says a further 300 a year might be eligible.
Ironically, today is meant to be the first day of a new, more harmonious age in relations between parents and education authorities. A new code of practice for pupils with special educational needs has been designed to make sure that their problems are dealt with swiftly and sympathetically. The code is backed by a special needs tribunal, which will hear from parents who are unhappy with the treatment they have received at local level. However, it is unlikely to stem the flow of cases to the courts.
The tribunal may be able to resolve some of the 150 cases a year that currently go to judicial review at the High Court, but it will not be able to award compensation. If it decides that a child has not received the right advice or help, he or she could then sue for damages.
The Lords' decision involved two former pupils, Richard Keating, 22, of Bromley, Kent, and Mark Christmas, 20, of Hampshire, along with an existing pupil named only as 'E' from Dorset. Mark and 'E' are dyslexic, and both claim that their local authorities failed to diagnose their conditions at the appropriate time. Both were sent to expensive independent schools by their parents as a result. Mr Keating says his intellectual development was impaired because Bromley allegedly failed to find him a school place for periods totalling three years and then placed him in a special school, despite the fact that he had average intelligence.
Mr Keating's solicitor is Jack Rabinowicz, well-known for his championing of special educational needs cases. He already has another 20 families waiting to launch their own legal actions if the House of Lords confirms the Appeal Court's judgment. 'At the moment most education cases relate to trying to correct wrongs, for example if a child is not getting the right provision. This will open up a totally different area where parents will be able to say that a school has failed their child,' he said.
John Wright, administrator of the Independent Panel of Special Educational Advisers, deals with up to 1,000 special needs cases a year and believes that in about one-third there are grounds for a compensation claim. He said the tribunal would not be able to stem the flood of cases even though it would provide a staging post on the route to the courts. 'Although we have strengthened the appeals system, the type of cases where negligence has arisen will continue to happen unless local authorities get their acts together. Unless they take fright at the idea of being sued and tighten up their procedures, a lot of parents will sue them as well as going to the tribunal,' he said.
Trevor Aldridge, the tribunal chairman, hopes that new time-limits imposed on local authorities will speed up decisions on the education of children with special needs and eliminate some cases which could be brought on the grounds of an inordinate delay.
However, he admits that there could still be cases where court action is brought for damages. Parents will have to go to the tribunal before they go to court, but if the tribunal decides they have been wronged, they may go on to take legal action, armed with its findings. 'The tribunal will offer no legal aid and therefore the appearance of lawyers isn't likely to be frequent. If the lawyers want to make hay, they are probably going to continue to try and make hay in the courts,' he said.
'NO ONE ELSE SHOULD HAVE TO SUFFER THIS'
Not long after Mark Christmas started school it became obvious that something was wrong. But it was six years before his dyslexia was diagnosed, and by that time he had lost the chance of a normal education.
'He wasn't slow but he wasn't learning. He was very naughty. His infant teacher sent word that he sensed frustration with letters,' said his mother, Marion.
Marion and Mark have been pursuing their grievance against Hampshire County Council ever since he was 14 - he is now 20 - and victory seems, finally, to be in sight. Mark's is one of three test cases that will go to the House of Lords next month, and may help him and hundreds of others like him to win compensation.
When he was 11, Mark went to an independent school that helped pupils with behavioural difficulties, and it was there that his dyslexia was discovered. He has since learnt that he has an IQ of 118 - well above average.
Both mother and son say the damages they are seeking are not of paramount importance, even though they believe his reduced earning power must have cost him many thousands of pounds.
'This is not about claiming damages. This about changing the system. We don't care if Mark doesn't get anything, as long as it doesn't happen to anybody else,' Marion said.
Mark hopes one day to become a registered mental nurse, but he still struggles with reading and writing and knows he will find it difficult to qualify. He has just found a job as a care worker with severely disabled children, and his activities with the scouts have taken him to the Gambia and Everest.
Without the help of his parents he would not have come this far, he said, but his main point was to save others from having to suffer the same traumas in future.
'I don't want this to happen to my children or grandchildren. I don't want to go through what I put my parents through,' he said.
'THE ACT SAYS: A SCHOOL FOR EVERY CHILD'
For most of his first six years in education, Niki Crane was quite happy at his local primary school in Hesketh Bank, near Southport, Lancashire, but now his parents have been told that the state system can no longer cope with him. They believe they may have a case for negligence against their local education authority.
Niki, aged 11, was born with severe brain damage - the cause was never established. His parents, Wendy and Pete, were told he would be totally incapacitated and that it might be best if they put him in an institution. But they persevered, and with intensive therapy he learnt to walk and speak.
'We both assumed Niki would go to a special school and made contact with the LEA. But when we chose one, the headmaster came to our home to see him, then sent a letter saying he was too disabled to go there,' Pete explained.
He sat down and read the 1981 Education Act, which said Niki was entitled to go to a local mainstream school if it was in his best interests, if the other pupils were not adversely affected and if it was an efficient use of resources.
Niki's case met these requirements and the local school took him on, with a full-time helper. Apart from one short spell in a special school after teachers began to feel they could not cope, he has been there ever since.
There have been problems, but none has been insurmountable, according to Pete. He believes that Niki was much happier and made far more progress there than he would have done at a special school.
Now the time has come for Niki to go to secondary school, and all his family's efforts have failed to convince Lancashire that his local comprehensive can cope. Pete and Wendy will keep him out of school rather than allow him to go back into special education.
Pete is convinced that the family has a case against Lancashire. 'If my son is not in the local secondary mainstream school then the LEA has been negligent under the 1944 Act, which says a local school should be provided for all children. There's a full stop there. It doesn't say 'apart from the disabled',' he said.