Iain Duncan Smith should resign as work and pensions secretary after it emerged more than 4,000 people have died within six weeks of being found "fit for work" by the department, Labour leadership candidate Jeremy Corbyn has said.
On Wednesday the government was forced to release figures that showed that between December 2011 to February 2014, 4,010 people died after being told they should find work following a "Work Capability Assessment".
The DWP stressed that "any causal effect between benefits and mortality cannot be assumed from these statistics".
Corbyn told a leadership hustings hosted by the Daily Mirror the figures were "frightening and so disgusting" and that people should not be declared fit for work when they were clearly not. "Yes he should resign," Corbyn said of Duncan Smith. "He should never have been appointed."
Earlier on Wednesday, Labour leadership candidate Andy Burnham called for a "national debate" in light of the revelations. "These are shocking figures that for the first time show the human cost of this Government's punishing benefits regime," he said.
"It raises serious questions about this government's punitive approach to people on benefits. We now need an urgent national debate about these figures, and if elected Leader I would call a full-day debate in Parliament at the first available opportunity.
He added: "This Tory Government has been playing politics with the lives of vulnerable people."
A DWP spokesman said: "The mortality rate for people who have died while claiming an out-of-work benefit has fallen over a 10-year period. This is in line with the mortality rate for the general working-age population.
"The government continues to support millions of people on benefits with an £80 billion working-age welfare safety net in place."
It is the second time Duncan Smith has faced calls to resign in the space of one week. On Monday, Duncan Smith dismissed demands from Labour MP Debbie Abrahams that he quit following revelations the department had made up quotes.
The department was caught out fabricating testimonials from people praising the government's welfare system. However Duncan Smith dismissed the idea he should quit said it was "nothing to do" with him and that "at no stage" did he see made up quotes.