Fewer claimants are being found eligible for Employment and Support Allowance (ESA) despite government claims that the benefits system is providing greater protection for disabled people.
More than 5,000 fewer people were granted ESA in the last three months for which data is available than in the previous quarter.
In fact, during this period statistics showed the overall proportion of claims approved for ESA fell to just 23%.
However, there was a small rise in the number of people qualifying for the most severely affected support group where no work activity is required.
Since the benefit was introduced in 2008 only 7% of those who applied have been found disabled enough to qualify for the support group, according to the new figures.
A further 17% were required to perform tasks as part of the work related activity group, which also includes a smaller level of payment than the support group.
More than a third (38%) have been found ineligible for the benefit following a work capability assessment (WCA), with 36% not completing their claim.
Reasons for not completing a claim range from those who choose to give up to some who die before it is completed.
The statistics cover the benefit's inception in October 2008 until the end of February 2011, with the three months to February being the newest data available.
In that quarter, 400 more claimants were approved for the support group than in the previous three months (13,000, 8% of the total, compared to 12,600, 7.6%).
However 5,700 fewer claimants were awarded the work related activity benefit (25,300 compared to 31,000) which reduced the success rate of applications to 15.8% from 18.8%.
Overall, applications were down 2.9% from 165,000 to 160,100 during the period.
[asset_library_tag 3596,The full data spreadsheet is available here.]
The Department for Work and Pensions (DWP) statement said that Ministers believe the increase in the number of people going into the support group shows that the changes that have been made to the WCA are starting to make a difference and more people are getting long term unconditional support.
Chris Grayling MP, the Employment Minister, added: "We are seeing an increase in the number of severely disabled people being given long-term unconditional support, which shows that our reforms to the work capability assessment are starting to work.
"However, it's clear that the majority of new claimants to sickness benefits are in fact able to return to work.
"For those that need additional help our new work programme is up and running and will tailor support to people's needs so that they can overcome whatever barriers they face."
The WCA has been widely criticised by charities and disability rights groups who have also targeted Atos Healthcare, the outsource company that conducts the interviews.
