Nearly a third of Redbridge residents claiming Incapacity Benefit were deemed “fit for work” in recent tests but disability campaigners say authorities “fail to understand” some conditions.

Out of 1,870 residents reassessed between October 2010 and August 2012, 550 were taken off the benefit, equating to 30 per cent.

It was the fourth-highest proportion of people found able to work in London.

The benefit, which has now been replaced by the new Employment and Support Allowance, was paid to people who cannot work because of a disability or illness.

Claimants must undergo a Work Capability Assessment or lose the benefit.

Rigorous tests are carried out in person by Atos Healthcare, which then makes recommendations to the Department of Work and Pensions.

But the firm has come under fire from disability campaigners who say thousands of claimants have wrongly had their benefits revoked.

Many “fit to work” judgments give rise to appeals, 37 per cent of which are upheld nationally.

Jon Abrams, from Redbridge Concern for Mental Health, said authorities’ lack of understanding of mental health problems stopped people accessing the benefits they deserved.

He added: “People with mental health problems have long had inferior access to disability benefits because of the failure of authorities to understand or respect their difficulties.”

Assessments seek to gauge the level of people’s difficulties using a points system intended to account for mental and physical illness.

Employment minister Mark Hoban said the new system was “fairer and more accurate”.