What were Iain Duncan Smith's 'welfare reforms' really about?

Whatever Iain Duncan Smith meant by his assault on benefits, it has failed – and the government's rhetoric has frightened the most vulnerable in the process.

But no welfare reform is failing more damagingly or harming more vulnerable people than the national rollout of employment and support allowance (ESA) and the now infamous Atos work capability assessment.

Sue Marsh assesses the Secretary of State for Work and Pensions and finds him unfit for purpose.

• Guardian