The Chancellor's plans for a £1.3 billion a year cut in disability benefits have been met with fierce opposition from within his own party, disability campaigners and the Labour party.
But how exactly would the measure work, how much does he think it would save and who would be affected?
The Chancellor's proposal
In the Budget, Chancellor George Osborne outlined cuts to Personal Independence Payments (PIPs) for disabled people which he said would save more than £4 billion by 2020-21.
The changes to PIPs will see up to 640,000 people affected by tighter assessment criteria but Mr Osborne has insisted the new system will be fairer as it will ensure that the money is given to the people who need it most.
The Institute for Fiscal Studies forecast that 370,000 claimants would lose an average of £3,500 each under the proposal.
What are Personal Independence Payments (PIPs)?
Personal Independence Payments (PIPs) replaced the Disability Living Allowance (DLA) for working age claimants in 2013.
The implementation was controversial from the beginning when some people were made to wait months before being assessed causing significant distress.
People on PIPs can claim an additional living allowance between £21.80 and £139.75 a week depending on a points systems which assesses how their condition affects their daily life.
It is aimed at helping the disabled live more independently by providing money for aids that will assist them with preparing food, washing and bathing, going to the toilet and dressing and undressing.
After an independent review the Department for Work and Pensions (DWP) found that the number of people claiming the daily allowance aspect of PIPs had tripled in 18 months up to December 2015, solely because of the use of aids or appliances.
The DWP insists most of this equipment is already supplied free by the NHS and local authorities, or can be bought for a low one-off cost, which means people do not need this aspect of PIPs.
PIP is made up of two parts called daily living and mobility, and each can be paid at either a standard or enhanced rate.
A second independent review of PIP is due by April 2017.
Will the changes to disability benefits take place?
The government has faced a wave of criticism since the plans were announced on Wednesday and a group of at least 20 Conservative backbench MPs have written a letter threatening to rebel and force the Chancellor to rethink the policy.
The Conservatives only have a slender majority so it is possible that the plans will be defeated in Parliament like changes to tax credits which were also part of the Chancellor's plans to cut £12bn from the welfare bill.
Education Secretary Nicky Morgan has already indicated that the idea could be watered down in the face of a backbench revolt.
And Work and Pensions Secretary Iain Duncan Smith wrote to Tory MPs to insist that consultations were continuing.
The government has also insisted that the overall spending on disability benefits is going up and many disabled people will continue to receive benefits.
But it will have to work hard to convince those who are firmly opposed to these changes.