Iain Duncan Smith has claimed he could get by on £53 a week - the amount some benefit claimants live on.
The Work and Pensions Secretary currently earns £1,581 a week after tax.
But when asked on BBC Radio 4's Today programme if he could live like that, he said: "If I had to I would," and defended the legion of benefit cuts taking effect this month.
He said: "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."
An online petition has now been set up, demanding that: "The current The Work and Pensions Secretary, to prove his claim of being able to live on £7.57 a day, or £53 a week.
"Iain Duncan Smith would be called upon to live on this budget for at least one year. This would help realise the conservative party`s current mantra that 'We are all in this together.'"
Having shot to 1,000 signatures in 23 minutes, it currently has 2,578.
