Amidst concerns that fit to work tests have been found to be unfair and too rigorous, the Government has been criticised for not regulating the firm that won the contract for undertaking the tests, Atol, strictly enough. The company carried out approximately 738,000 medical checks on claimants, and was paid £112m in the last financial year, but many of the decisions it made concerning whether people were fit for work or not were taken to Tribunal, with nearly 40% of those cases resulting in the decision being overturned.

A National Audit Office (NAO) analysis of the system criticised the Government for failing to set “sufficiently challenging” targets or enforce financial penalties for “under performance” despite a recent BBC Panorama investigation suggesting that the target-driven system encouraged the company to make incorrect decisions in order to get people off ill health benefits.

The DWP used the test results, known as work capability assessments, to decide whether people were fit to work or eligible for Employment and Support Allowance (ESA).

The NAO’s Comptroller, Amyas Morse, said it was hard to know whether changes to the tests were needed, saying:

“It is difficult to assess, as the department does not routinely request feedback on the rationale for Tribunal decisions. Without such data it is not clear whether any changes in the medical process are needed.

“This is a damning assessment of the failure of the Government to get value for money for the taxpayer or properly hold Atos to account for the chaos and confusion at the heart of the work capability assessment. The Government must reflect on this scathing report and bring forward serious proposals for reform.”

The DWP had previously admitted that Atos had not carried out some fitness testing within the agreed time limits, and performance had been “below the standard” since mid-2011.

The NAO claims just 10% of the penalties triggered by poor performance had been applied and added that the DWP’s negotiating position has been undermined by “inaccurate forecasting” of the number of people likely to need a medical test.

The criticisms come in the same week that the former Director General of the British Chambers of Commerce said significant numbers of sickness absence claimants, who are not given any encouragement to return to their jobs, soon realise they do not need to return to work if they can stay at home on benefits.

David Frost, who was commissioned by the Government last year to lead a review on how to cut the long-term sickness absence bill in the public and private sector, said the current system is “flawed”.

There have been calls for the tests to be revised, including from Professor Malcolm Harrington, who was hired by the Government to review the process and has since resigned from his post.