Ministers have pledged to publish a long-buried internal study into the emotional and financial impact of fines and prosecutions incurred by tens of thousands of unpaid carers for falling foul of strict carer’s allowance earnings rules. The Department for Work and Pensions (DWP) agreed to carry out the research at the insistence of MPs five years ago after they criticised it for having no understanding of the misery and hardship inflicted on unpaid carers by its policies. Mims Davies, the minister for disabled people, told MPs on the work and pensions select committee on Wednesday that the study, which the DWP has consistently refused to publish, would be released “shortly”. The Guardian has in recent weeks documented the despair and stress experienced by unpaid carers forced to pay huge fines – and sometimes taken to court on fraud charges – after unwitting breaches of carer’s allowance earnings limits, that the DWP allowed to run on for months and sometimes years. However, Davies told MPs there were no plans to review carer’s allowance despite growing calls to overhaul its punitive earnings rules. She said that “things go right” for 95% of carer’s allowance recipients, though she conceded those who found themselves having to repay overpayments “would not necessarily be feeling that”. Davies apologised over the “disturbing” case of a 92-year-old woman with advanced Parkinson’s who was ordered to pay back nearly £7,000 after falling foul of harsh disability benefit rules that insist it is the responsibility of claimants to inform officials when their circumstances change. The Guardian revealed last week how the DWP refused to waive the woman’s overpayment even when her unpaid carer daughter told them her mother had not been not well enough to inform it of a change in her circumstances five years earlier. Davies said: “That particular case – anybody reading that would find it disturbing in what they see in the newspaper.” She claimed it was an exception, saying: “I don’t want people watching this [hearing] to think this is any kind of normality they should expect. The balance here between fraud and error, getting it right for the taxpayer and being able to support people and not having this situation is key.” The case was described as “beyond the pale” by government dementia adviser Johnny Timpson when he resigned his role this week in protest at the DWP’s treatment of unpaid carers and their families. The committee chair, Stephen Timms, said latest official figures showing 34,500 unpaid carers had incurred overpayments last year suggested the DWP had failed to make any progress since the committee last looked at the issue in 2019. At the time, officials claimed new technology would solve the overpayments problem. Davies said she thought things were “better” than they had been but declined to elaborate. She said: “I want carers and those watching to be mindful things in the national press will be concerning. We are a very large department – 80,000-plus people doing a huge amount of benefit administration. There is always going to be things that go wrong and we are very sorry for that.” Responding after the committee, Helen Walker, the chief executive at Carers UK, said: “Carers up and down the country will be deeply disappointed by the minister’s message that carer’s allowance – the lowest benefit of its kind – will not be raised in line with other similar benefits and that there are no plans to change any of its inflexible and punitive eligibility criteria.” The issue was raised at prime minister’s questions by the Liberal Democrat deputy leader, Daisy Cooper. She said carers had been “hounded” by the DWP for minor infringements of earnings allowances, “all because the government failed to do anything about a problem they have known about for years”. Responding, the deputy prime minister, Oliver Dowden, said: “In respect of allegation of overpayments, of course appropriate discretion should be shown but if it is the case that there have been erroneous overpayments it’s right and proper for the taxpayer to be able to recuperate those.”