A petition urging Iain Duncan Smith to prove his claim that he could live on £53 a week has attracted more than 100,000 signatures in less than 24 hours.
The work and pensions secretary made the claim in an interview on BBC Radio 4's Today programme as he sought to defend swingeing welfare cuts. He said he planned to making the welfare system fairer and give people the chance to "break free" of benefits.
Duncan Smith said it was "only fair" that 660,000 families who were on benefits and living in social housing should lose £14 a week if their home was regarded as under-occupied - the so-called "bedroom tax".
The former leader of the Tory party, who is reported to earn around £130,000 a year as a cabinet minister, insisted he could live on £53 a week - £7.57 a day - after a market trader told the programme that he lived off that amount after his housing benefit was cut.
"If I had to, I would," Duncan Smith claimed.
That prompted the petition which mocked the Conservative party's mantra, "We are all in this together", to challenge the minister to put his money where his mouth is.
More than 120,000 people signed the petition less than 24 hours after it was launched. A petition with 100,000 signatures is enough to raise a debate in Parliament.
The petition, on change.org, added: "This petition calls on Iain Duncan Smith to live on this budget for at least one year. This would help realise the Conservative party's mantra that 'We are all in this together'.
"This would mean a 97 percent reduction in his current income, which is £1,581.02 a week or £225 a day after tax."
Duncan-Smith's claim was made after 51-year-old stallholder David Bennett told the Today programme that he earned £2,700 in 2012 after working 50-70-hour weeks. He added that now his housing benefit had been cut - despite his children staying with his several times a week - he was forced to live on £53 a week.
Smith said the coalition's welfare cuts were an attempt to get the system "back in order".
He added: "We are in an economic mess. We inherited a problem where we simply do not have the money to spend on all the things people would like us to do.
"What I am trying to do is get this so we don't spend money on things that are unfair.
Reform and change
"These reforms ... yes, they are about holding back on the costs. But critically people will say this is modernising a welfare system.
"What we are trying to do is get control of the welfare bill without actually slashing [it] or attacking people. We are trying to reform and change it."
Dominic Aversano, who drafted the petition, said: "Iain Duncan Smith's comments struck me as both fanciful and insincere.
"I believe many people feel there is a dangerous division forming in this country between the rich and poor, and to bridge this, and prove we truly are all in this together, he should show leadership and prove he can survive in the conditions he expects others to endure. "
Shadow work and pensions secretary Liam Byrne said of the welfare cuts: "This wicked bedroom tax is going to rip neighbour from neighbour, force vulnerable people to food banks and loan sharks, and end up costing Britain more than it saves as tenants are forced to go homeless or move into the expensive private rented sector.
"It is the worst possible blend of cruelty and incompetence. The government must think again and drop this tax now."