Scores of parents challenge councils on the educational support children as young as three receive.
In the past four academic years, 368 parents have tackled Sussex councils on the support children with special educational needs receive and where they are schooled.
The cases have cost Brighton and Hove, and East and West Sussex councils more than £276,000 in combined legal fees according to figures obtained by The Argus.
In the most extreme cases, councils have fought disability discrimination claims.
Brighton and Hove City Council has been taken to tribunal 31 times since 2010 and spent £80,000 in legal fees.
Just under half the cases were won by the parents. The council says the number of cases has fallen from 13 in 2010/11 to one in 2013/14.
East Sussex County Council has seen the number of tribunals fall from 55 in 2010/11 to 23 in 2013/14 while costs fell from £75,000 to £9,000.
West Sussex County Council is the only authority that has seen the number rise with 2013/14 already doubling.
Councillor Sue Shanks, chair of Brighton and Hove City Council’s children and young people committee, said the fall in cases was deliberate policy. She said: “We seek to make positive contact with parents from the outset and ensure they receive a personalised service. “This offers constructive solutions encompassing education, health and care.”
West Sussex County Council said it had a relatively low rate of appeals to tribunals as many were resolved without a hearing.
East Sussex County Council said that many of their cases were linked to the fact that it has four independent special schools within its borders with parents appealing decisions not to place a child at one of these schools.
A spokesman said: “The number of cases referred to tribunal represents a very small proportion of the 2,700 children with special educational needs we currently support.”