The Department for Work and Pensions (DWP) is facing questions over why it failed to release the results of a pilot project that was supposed to correct a fatal flaw in its “fitness for work” test.

DWP had promised a judge that the pilot project would test ways of making the work capability assessment (WCA) safer for claimants with mental health conditions and learning difficulties, by ensuring that the necessary medical evidence was collected from their healthcare professionals.

Many disabled people claiming out-of-work disability benefits have been unable to prove they could not work because the WCA process has been focused on an unfair and discriminatory face-to-face assessment, and they were unable to provide enough written evidence to back up their cases.

Ministers promised a tribunal appeal hearing two years ago that they would carry out the pilot project, but nine months after it ended they do not appear to have passed on its findings to the lawyers representing the two disabled people who took the long-running legal case, or even informed them that the pilot project had finished.

The Mental Health Resistance Network (MHRN), the user-led group that was behind the legal case, said this week that this apparent failure was “extraordinary”.

Denise McKenna, MHRN’s co-founder, said this suggested that DWP had not addressed the WCA’s fatal flaws.

She said: “I am not confident that what they have come up with is going to be robust enough, that it’s going to include other medical evidence in enough cases.

“The other thing is I am not confident that they will pay any heed to the medical evidence anyway. They just don’t want to take account of medical evidence.

“They just want everything to be resting on that Mickey Mouse interview, that Mickey Mouse assessment.”

MHRN and other activists believe that many disabled benefit claimants – particularly those with mental health conditions – have lost their lives because of DWP’s failure to collect all the medical evidence necessary when assessing whether people were eligible for employment and support allowance (ESA).

The legal case had concluded that the WCA discriminated against some disabled people with mental health conditions and learning difficulties.

DWP has now admitted that it completed this pilot project – which took place in Glasgow – last May.

DWP only admitted that the pilot project had been completed in a response to a Disability News Service (DNS) story about Mark Wood, a disabled man who starved to death after he was found “fit for work”.

His mother, Jill Gant, had questioned why DWP had still failed to act on the issue of further medical evidence, nearly seven years after a coroner in another case had warned ministers that they needed to address the problem, or risk other disabled people losing their lives.

She had tried for two years to persuade DWP ministers Mark Harper and Priti Patel to act.

Wood died in the summer of 2013, more than three years after the coroner’s letter to DWP ministers.

His mother blames his death on the failure of DWP and Atos assessors to collect the medical evidence needed to demonstrate that he was eligible for ESA.

A DWP spokesman said the department had updated guidance for the assessors who carry out WCAs – now carried out by the US company Maximus, rather than Atos – but that he could not say how the guidance had changed.

He said: “The outcomes have been that we’ve updated our general practices and guidance for assessments, which fits in with our ongoing process to ensure the WCA provides the right service for claimants.

“The new guidance provides examples of situations when further evidence should be requested by healthcare professionals in the WCA process, especially for people with a mental health condition.”

But he said he could not release the new version because the department was “currently in the midst of discussing guidance and the training for healthcare professionals with our provider”.