Iain Duncan Smith has been accused of "striking fear into the hearts" of the sick and vulnerable with his plans to tighten the welfare system.
The Work and Pensions Secretary declared that work is "good for your health" and can help people recover from illness as he announced proposals to lower the number of disabled people claiming benefits.
Mr Duncan Smith told ITV News that the existing system was too "simplistic" for judging whether someone was either fit for employment or signed off entirely.
He insisted too many people with "common" mental illnesses are reliant on state payouts, when they could be earning a wage.
Instead the Cabinet figure wants benefits assessments to check what tasks people could do and hopes the changes will aim to halve the gap between the number of disabled and non-disabled people in employment.
But Labour leadership candidate Andy Burnham said the plans masked the department's failings under Mr Duncan Smith and will "cause even more anxiety" for those reliant on state financial aid.
The work capability assessment system that determines if someone will receive the employment and support allowance (ESA) has been dogged by controversy since its introduction under Labour and has undergone further changes under the coalition government.
Mr Duncan Smith said ESA was supposed to reduce the number of people on incapacity benefits by one million, but since 2010 there has been a fall of just 90,000 - and plans to reform the process will now be drawn up.
He said nearly one in four people claiming jobseeker's allowance have a common mental health condition and need more support to find, and stay, in employment, adding that claimants' health could improve by taking a job.