Reforms to disability benefits will end the 'ridiculous' system that gives people lifetime awards, Iain Duncan Smith has claimed.
The Work and Pensions secretary was speaking as disability living allowance (DLA) begins to be replaced by the personal independence payment (PIP), which charities say will remove support from many in real need.
Mr Duncan Smith said claims in disability benefit have more than doubled in some parts of the country ahead of the changes.
His comments came as nearly half a million people have called on the Tory cabinet minister to live off £53 a week for a year in a petition being delivered to his office today.
"Seventy per cent of people on it have lifetime awards which means no one sees you ever again. It doesn't matter if you get better or your condition worsens - it's quite ridiculous," Mr Duncan Smith told the Daily Mail.
"We've seen a rise in the run-up to PIP. And you know why? They know PIP has a health check. They want to get in early, get ahead of it. It's a case of 'get your claim in early'."
He added that rigorous new health checks for claimants were "common sense".
It is the latest in a series of radical welfare changes which started on Saturday, when working-age benefits and tax credits were cut in real terms with the first of three years of maximum 1% rises - well below the present rate of inflation.
Trials will also begin this month in four London boroughs of a £500-a-week cap on any household's benefits and of the new Universal Credit system.
This morning protesters, angry at sweeping welfare reforms and the minister's claim he could live off £53 a week if he had to, will deliver a petition bearing 450,000 names to the Department of Work and Pensions at 10.15am.
Mr Duncan Smith has already dismissed the petition as "a complete stunt".
Musician and part-time shop worker Dominic Aversano, from Twickenham, near London, started the petition on campaigning website Change.org.
He will deliver the petition to Caxton House in Tothill Street with disability campaigners who say they are at the sharp end of welfare reforms.
Mr Aversano, 28, said: "When I started this petition I never imagined the level of support it would get, and the amount of encouragement people would give me.
"It has sent a powerful message to this Government, showing the level of opposition to their vicious welfare cuts.
"Online petitions have become a powerful democratic tool outside traditional political institutions and can turn the tables on those in power.
"Iain Duncan Smith started the week dismissing the suffering of the poor, then he called this petition a 'stunt'.
"It's now nearly half a million strong and it's telling that he continues to ignore such an enormous outpouring of anger and disapproval."
Protester Heather Simpson, 46, from Battersea, London, said: "My husband is a nursery worker but his low salary means we are forced to claim housing benefit.
"As a wheelchair user the housing association provided me with a three bedroom house, and now we're going to be hit by the bedroom tax.
"I signed the petition because I want Iain Duncan Smith to live on £53 per week so that in future he might not be so quick to dismiss the challenges faced by the people living in poverty."
Brie Rogers Lowery, UK director of Change.org said: "This is a remarkable campaign. It's far and away the largest and fastest growing petition in the history of Change.org in the UK and is a clear example of how social media has put the power to shift political debate into the hands of the people.
"Anyone, anywhere can come to Change.org and start a campaign as powerful as the one Dominic launched last week."