The data showed that more working-age women are claiming Universal Credit for health reasons than men, though the reverse was the case for people above retirement age. 

DWP said 38pc of claimants were aged over 50 and 10pc were under 25.

Of the 2.6 million health claims processed by DWP over this four-year period, 16pc were rejected, while 19pc were classified as “limited capability for work”, meaning they do not receive extra money but less of their benefits are clawed back by the state once they start working.

The Tories want to scrap the so-called work capability assessment that determines UC benefit awards as part of a benefits overhaul aimed at saving £12bn a year by the end of the decade.

Labour also vowed on Thursday to support more people into work. “Too many people are out of work or not earning enough,” it said in its manifesto, blaming “long waits for treatment of health conditions, particularly mental health”

It added: “Our system will be underpinned by rights and responsibilities – people who can work, should work – and there will be consequences for those who do not fulfil their obligations.”

Economists have warned that Britain’s worklessness crisis is threatening growth, with the number of adults neither in a job nor looking for one due to ill health now at a record high of 2.83 million.

Overall inactivity rose to more than 9.4 million in the three months to April, the highest since 2011.