Thousands of people with progressive conditions such as Parkinson's and MS are being told they could recover enough to look for work, according to charities.
The government's controversial Work Capability Assessment is again under fire after a coalition of four leading charities claimed that 45% of people were told they would be able to work again following assessment for Employment Support Allowance.
Parkinson's UK, MS Society, National Rheumatoid Arthritis Society and Cystic Fibrosis Trust have called for the abolition of the system saying it is "farcical" and "defies belief".
Between 2008 and 2011, 13,600 people with cystic fibrosis, multiple sclerosis, Parkinson's or rheumatoid arthritis applied for Employment Support Allowance, figures show.
Nearly half were placed in the Work Related Activity Group (WRAG) after being assessed for Employment Support Allowance, where charities claim they should have been in the Support Group, which doesn't require the individual to seek work.
Sue Watson, from Leeds, is one of 580,000 people in England who suffer from Rheumatoid Arthritis.
On bad days it can make even the smallest movements intensely painful.
When she was forced to give up her work as an aromatherapist her Work Capability Assessment placed her in WRAG.
"It has a detrimental effect because stress affects rheumatoid arthritis," she says.
"So the stress of being felt that you're on the scrap heap and that you're not believed, and to think that I'm going to be forced to go back into work even though I can't, that had a huge impact on me."
Caroline Hacker, Head of Policy at Parkinson's UK said "This is the latest in a long line of unspeakable failures by Atos Healthcare (who carry out the assessments) and the Government when it comes to supporting those who need it most.
"To set up a system which tells people who've had to give up work because of a debilitating progressive condition that they'll recover, is farcical and simply defies belief."
A Department for Work and Pensions spokesman said: "It's ridiculous to suggest that we think people with degenerative conditions will 'recover'. However, it is important that we don't simply write people off. There is strong evidence that working can be beneficial for many people who have a health condition."
An Atos Healthcare spokesman said: "Our healthcare professionals are trained in the assessment of chronic and progressive conditions such as Parkinson's and understand that, sadly, some people's conditions will only get worse over time.
"However, the advice we are asked to give DWP concentrates on how individuals are affected by their illness at present.
"All decisions on the outcome of claims, for example whether they are placed in the WRAG or the Support Group, are made by DWP."
The charities though are calling for an end to a system which they say causes unnecessary stress and anxiety for people who are already in poor health.