The Coalition’s tougher rules on who can claim incapacity allowances will be felt most strongly in Labour’s heartlands of the north of England, Scotland and Wales, according to the study, which criticised the plan.
The report from Sheffield Hallam University, in the Deputy Prime Minister Nick Clegg’s constituency, warned that that “vast numbers” of people will be impoverished and left in distress as a result of the reforms.
Over the next three years, major changes are being introduced to incapacity benefit, including a tougher medical test for claimants, the re-testing of existing recipients of payments, and a limit on the length of time individuals are entitled to non-means tested benefits.
Disabled groups and charities have claimed the new tests are stigmatising the disabled and mentally-ill as “scroungers” in order to save money from the welfare bill.
Ministers insist that the reforms are not an attempt to stop “scroungers” but will help more people currently deemed unable to work find jobs.
The Sheffield Hallam report, which analysed pilot schemes and the Department for Work and Pensions’s own calculations, found that the impact of the reforms has so far “barely been felt”.
The current total of 2.6 million people on incapacity benefit will fall by about one million by 2014, under the reforms, although this is not a sign of “widespread fraud” in the existing system, according to the study.
Professor Steve Fothergill, co-author of the report, said: “The large numbers that will be pushed off incapacity benefits over the next two to three years are entirely the result of changes in benefit rules.
“The reduction does not mean that there is currently widespread fraud, or that the health problems and disabilities are anything less than real.”
He said the Coalition was presiding over reforms that will impact “principally on individuals and communities outside its own political heartlands”.
Merthyr Tydfil in Wales, Easington in County Durham, Liverpool and Glasgow are expected to be hit 10 times harder than for example Kingston upon Thames in London or Wokingham in Berkshire, the study found.
Prof Fothergill said the “most far-reaching changes to the benefits system for at least a generation” would “impoverish vast numbers of households and cause untold distress in countless more”.
“The incapacity benefit numbers need to be brought down, but this is not the way,” he said.
Chris Grayling, the employment minister, said the current system had seen “millions” of people “written off for years” and given no help to find jobs.
“That’s why we are retesting people to see if they have the capacity to work,” he said. “Our changes will make sure those in genuine need get more support and those who could and should be working are given the opportunity to do so.
“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.”