This month government MPs forced through a motion for a £30-a-week reduction in the ESA paid to those disabled people considered capable of undertaking "work-related activity".

The move sparked outrage: Yesterday three Tory MPs were asked to resign as patrons of disabilities after voting for the motion, while the Disabilities Benefits Consortium, an informal coalition of 60 national disability charities, described the decision as a "step backwards".

There has also been anger ever since Duncan Smith took over as work and pensions secretary over the administration of the tests for people to claim ESA (which had originally been introduced by Labour).

In 2013 the work and pensions select committee concluded that the system was "clearly causing claimants considerable distress and anxiety." Many felt that the use of outsourced contractors – first Atos and then Maximus – introduced a profit incentive into a system that was crucial for people's lives.

According to figures released last year, over 2,300 people died shortly after their benefits ended and they were declared fit for work between 2011 and 2014. The Department for Work and Pensions (DWP) insisted it was impossible to establish a direct link between people losing benefits and dying as it did not hold information on the cause of death.

A study in the Journal of Epidemiology and Community Health found that almost 600 suicides could be linked to DWP work assessments.