Work and Pensions Secretary Iain Duncan Smith has insisted he knows what it's like to be on the breadline as he dismissed a petition calling for him to live on £53 a week as a "complete stunt".
The petition, signed by almost 250,000 people, was started after Mr Duncan Smith said during a radio interview that he could get by on that amount.
The remark followed a challenge by market trader David Bennett during a BBC Radio 4 Today programme item on the Government's sweeping reforms to the welfare system.
The online petition, hosted at www.change.org, said: "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 current mantra that 'We are all in this together'.
"This would mean a 97% reduction in his current income, which is £1,581.02 a week, or £225 a day after tax."
Chingford and Woodford Green MP Mr Duncan Smith told a newspaper that he had experienced two periods of unemployment and knew what it was like "to live on the breadline".
He said: "This is a complete stunt which distracts attention from the welfare reforms which are much more important and which I have been working hard to get done.
"I have been unemployed twice in my life so I have already done this. I know what it is like to live on the breadline."
Chancellor George Osborne was also challenged about whether he could survive on the £53 weekly income Mr Bennett claimed he was left with.
"I don't think it's sensible to reduce this debate to an argument about one individual's set of circumstances," Mr Osborne said in response to questions following a speech in which he defended the welfare reforms.
"We have a welfare system where there are lots of benefits to people on very low incomes."
The focus on the Government's benefits shake-up came as 660,000 social housing tenants deemed to have a spare room began to lose an average £14 a week in what critics have dubbed a bedroom tax.
Wider welfare and tax changes coming into force this month will also see council tax benefit funding cut, and working-age benefits and tax credit rises pegged at 1% – well below inflation – for three years.
Disability living allowance is being replaced by the personal independence payment, while trials are due to begin in four London boroughs of a £500-a-week cap on household benefits, and of the new universal credit system.