One in five recommendations by the Atos IT firm that suggest benefit recipients are "fit for work" are overturned at appeal.
Of the claimants which Atos found fit for work, 20% were overturned either by Department of Work and Pensions staff or appeal tribunals, government figures have shown.
That’s 150,500 people who were assessed as able to work who were subsequently judged to be deserving of Employment and Support Allowance (which is replacing incapacity benefit).
The figures will anger anti-cuts and disability campaigners, who claim that inaccurate testing is forcing disabled people to live in poverty and in some cases driving them to take their own life.
More than two million people are currently being assessed as part of a government drive to encourage people off benefits and back to work. Atos performs the test, but the final decision to cut or award benefits rests with the DWP.
Sheila Gilmore, MP for Edinburgh East, was sent the figures after tabling a parliamentary question on the matter. She told the Huffington Post UK she didn’t think the real issue was being addressed.
“I was hoping to find out whether DWP was simply rubber stamping the Atos test. That would account for the high numbers being overturned when they got to appeal, when more information was presented. I wanted to know- is this test being used as the the decider rather than other information?”
A spokesperson for Atos points out that the company simply provides a test (the Work Capability Assessment) and that the government weighs up its decision to cut or award benefits after being given more information about claimants.
DWP say the 'one in five' figure comes with a caveat: that often more information is being presented at appeal than they were originally party to.
Ms Gilmore says she thinks a miscommunication at this level may be where the process is going awry:
“I’m hearing from my constituents that people are trying to give DWP other information like doctor's notes, but it seems like DWP aren’t looking at the whole picture and forcing people to go through a lengthy and expensive appeal process. If that was all looked at it at the beginning it would be much easier. “
Disability campaigner and writer Sue Marsh, who suffers from severe Crohn's disease told the Huffington Post UK
"The point for me is that appealing is a horrible process. Can you even imagine trying to deal with cancer or an MS diagnosis only to find someone has decided that you are fit to work?
"Then, in the middle of an incomprehensible life adjustment you are expected to fight the shame of the rejection, put together endless papers and evidence, deal with tribunals, all for £94 a week?
"I fear that many, many people with legitimate claims are put off from appealing in the first place. This is a scandal in my opinion. I believe the system intentionally forces many into un-necessary appeals in the hope that they will just give up.
Kaliya Franklin, who writes the blog “benefit scrounging scum” told Huff Post UK the crucial issue was “ whether Atos are just getting things wrong, or whether the tribunal service are interpreting descriptors differently to the interpretation imposed by DWP. It may be some combination of the two. “
She said that its the DWP, not Atos that she holds responsible for the high level of error, adding: "the DWP set descriptors, interpretations and targets that aren't targets so it is all ultimately their responsibility.”
Dame Anne Begg, Labour MP and chair of the Commons work and pensions select committee said: “This is evidence that whatever is happening, whether it is the contract between Atos and DWP that is at fault or indeed the way the assessment is being interpreted by Atos staff, they are getting it wrong in a very high proportion of cases.
“And to find out that almost 14,000 people were found fully fit for work when they should have been in the support group... that is a lot of people.”
In August, the Citizens Advice bureau renewed its call for the government to impose financial penalties on Atos for every inaccurate work capability assessment report that they produce.
"Mistakes by Atos have a human cost and a cost to the taxpayer," said Gillian Guy, Citizens Advice CEO.
"Getting medical assessments right first time is absolutely essential to ensuring that seriously ill and disabled people get the support they are entitled to, and cutting the number of unnecessary appeals."
Disability campaigner and blogger Lisa Egan flagged up to the Huffington Post UK the number of people who have died from their illness’s after being found fit for work. "I keep them bookmarked on my browser," she said.
Cancer sufferer Cecilia Burns died in August following a month battle after Atos judged her “fit to work” Her benefits were re-instated three weeks before she died.
Larry Newman, who died from lung cancer, was scored zero points in an Atos disability test in 2011. He passed away before being able to successfully appeal his score. His widow, Sylvia Newman, told the Guardian that one of the last things he said to her, as doctors put him on a ventilator, was: "It's a good job I'm fit for work."
Before her death Ms Burns from County Tyrone in Northern Ireland told the BBC that she felt the medical test was a “joke” and said she was disgusted by her experiences. She told the BBC she felt "that I don’t count, I don’t matter”.
Reports of suicides motivated by fear of the tests or following a negative assessment show the human cost of such tests, whether directly responsible for benefit cuts or not. Friends of Scottish writer Paul Reekie accused the government of fuelling the depression that led to his suicide after his body was found with no note, but just two letters that shown his beneftis had been cuts.
Atos told the Huffington Post UK: “We understand that applying for benefits can be an emotional time which is why we work hard to make sure that the service we provide is as highly professional and compassionate as it can be.
"We apply the DWP’s criteria and policy to all of the assessments we provide which is why they are in line with the final decisions made in the vast majority of cases.
“The assessment carried out by our staff forms an important but single piece of information used by the DWP to make a decision on benefit entitlement.
"Where the outcomes differ it does not necessarily mean that our assessment was inaccurate but instead the Department or Tribunal Service may have had access to further information that was not seen by Atos Healthcare.”
The DWP told the Huffington Post UK:
"If someone disagrees with the outcome of their Work Capability Assessment, they have the right to appeal.
"We are committed to help thousands of people move from benefits and back into work if they are capable while giving unconditional support to those who need it.
"Through a series of independent reviews we are working to make sure the WCA it is both fair and effective, and it is in everyone’s interest to get the system right.”