The authority is among several named and shamed by a leading charity for badly handling budget cuts which affect services for thousands of disabled people throughout the county.
It has been ranked among the bottom ten authorities in the country in a report by the think tank Demos, whose research was commissioned by the disability charity Scope.
A list of ten top-scoring authorities is claimed to show where cuts are having the least impact on the front line.
West Sussex appears in a list of ten bottom-scoring councils where cuts are said to be having the biggest impact.
A total of 152 authorities were claimed to have been surveyed by the think tank.
Responding to the report, a county council spokesman said the authority had to make £79m of savings over the next three years.
However, nearly 80 per cent of the cut to the council budget was being found not by service cutbacks, but by management improvements, streamlining the organisation and cutting bureaucracy.
He told the Observer: “Cuts to frontline services have been kept to an absolute minimum, but cannot be avoided completely. Where cuts to services have been made, the decision has been taken following consultation and ensuring alternative community services would be available.
“The report by Demos has been discredited by a number of professional organisations including the Association of Directors of Adult Social Services (ADASS).
“Trying to compare different councils in this way is meaningless. A number of councils didn’t respond to the Demos Freedom of Information request and others didn’t respond in full, so to present the results as a ‘scientific league table’ is completely inaccurate. ADASS themselves say Demos has ranked councils using criteria that are discredited.”
A statement issued by Scope said the research showed the level of cuts did not always coincide with cuts to the front line: the best councils were protecting their disability services.
“Many councils which introduced the same level of budget cut scored vastly differently on the coping scale, demonstrating councils have the ability to introduce measures that can reduce the negative impact on their disabled residents,” the statement added.
The research showed some authorities towards the bottom of the ranking were using crude calculations to identify their disabled population.
“These councils risk poorly planned cuts to services relied on by disabled people and their families,” it said.
Claudia Wood, author of the report, said: “It is a scandal that authorities are making cuts without an accurate grasp of the number and needs of their disabled populations. Decisions on the front line of disability services will make or break disabled people’s lives.”
Scope chief executive Richard Hawkes said: “We are calling on councils to put disabled people and their families at the centre of decisions that affect their lives.”