Plans to cut disability benefits could breach human rights laws, the government has been warned.
Ministers want to replace Disability Living Allowance (DLA) with a new Personal Independence Payment.
The government says the changes are designed to streamline the system as well as make cuts of 20%.
Disability lawyer Mike Charles told the BBC the moves could be unlawful if they denied individuals the right to quality of life.
The change would mean new assessment tests for claimants who would also need to have had a condition for six months.
'Equal playing field'
Mr Charles said: "The human rights act says individuals have a right to family life, have a right to a quality of life, the whole purpose of the DLA is to put them on an equal playing field with everyone else.
"Any proposal that fails to appreciate those fundamental rights could find it is an infringement of the law.
"My view is even if its not against the letter of the law, it is against the spirit of the law."
His opinion is backed up by other specialist disability lawyers.
Charities including Disability Alliance claim the proposals are not about simplifying the system but are about removing 380,000 claimants from it.
Disability charity Scope said it was unhappy that the mobility component of the DLA for care home residents, which supports people who need help getting around, would be scrapped.
Scope chief executive Richard Hawkes said: "We would say that that is quite a callous decision. It will result in people being prisoners in their own homes, they won't be able to do those daily things that everybody else would take for granted."
Janet Solomons, from north London, whose son Benji, receives DLA, said: "He lives in a residential care home where he has been for some 17 years now and he has benefits which includes the mobility allowance, which allows him to get out and about.
"It's a very specific allowance and it makes an enormous difference to the quality of life that he has in that home."
She said the impact of removing the DLA would be terrible: "He really enjoys going to a club on a Monday evening.
"It is only a couple of miles away but he needs a taxi to get there. If he did not have the allowance he just would not be able to go there."
The government, which claims the changes could reduce spending by 20%, says it is committed to helping disabled people live independent lives and that the changes are needed.
The proposals are part of a consultation process that ends on 14 February.
The Minister for Disabled People, Maria Miller, urged people to give their views before the consultation ends on the 14th of February:
She told the BBC: "It's really important that when people do give their input into the consultation that there is a realism about it.
"We are dealing here with a benefit which as I said is one of the largest benefits that's paid in the UK and that we need to make sure it's getting to the people who need it most."