Protesters, angry at sweeping welfare reforms, delivered a petition to the Department of Work and Pensions calling on Iain Duncan Smith to live off £53 a week for a year.
The Work and Pensions secretary claimed he could live off £53 a week if he had to but has dismissed the petition, which has 450,000 signatures, a stunt.
The minister for disabled people, Esther McVey, said changes to the benefit system are about "understanding disability in the 21st century" and adapting a system which will work better in the future.
Speaking about the Personal Independence Payment plans, Mrs McVey said: "What we've got to do is ensure the billions of pounds that we spend, really are focused on those people who need it the most."
She added that independent assessments would be carried out along the way, to make sure the Government is "getting it right."
Paralympian Sophie Christiansen, who won three gold medals at London 2012, fears she may be affected by the changes to disability benefit that will come into force today.
Speaking to Daybreak she said, "I use the money to actually make my life sustainable as it were, I use it for my wheelchair, my scooter, the extra care social services don't provide."
The work and pensions secretary Iain Duncan Smith has welcomed reforms to disability benefits will end the "ridiculous" system that gives people lifetime awards.
In an interview with the Daily Mail, he said: "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".
"There are websites dedicated to telling you how to avoid the pitfalls of making a claim for DLA. 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”.
Disability campaigner Jane Young has said that the new Personal Independence Payment benefit scheme will be "more restrictive" that the current Disability Living Allowance syste,
Ms Young who has musculo-skeletal disorder which affects her mobility, also said that she feared the changes in criteria would lead to some wheelchair users including herself, losing some support.
Click here to find a tool which checks how the Personal Independence Payment (PIP) scheme will affect you if you have a health condition or disability and are aged 16 to 64.
- The personal independence payment scheme is being introduced for people with a health condition or disability aged 16 to 64.
- From today, it will be introduced for new claims in Merseyside, North West England, Cumbria, Cheshire and North East England. It will be rolled out nationally from June.
- Currently, there are no current plans to replace Disability Living Allowance (DLA) for children under 16 and people aged 65 and over who are already receiving it.
- Some people may require an assessment to work out the level of help needed.
- Most people currently getting DLA will not by affected by the change until 2015, according to the government.
A new benefit which replaces the Disability Living Allowance for people with a health condition or disability aged 16 to 64 is introduced today.
The Personal Independence Payment (PIP) scheme will first be introduced for new claims in Merseyside, North West England, Cumbria, Cheshire and north-east England.
It will be rolled out nationally for all new claims from June 2013.