Employment and Support Allowance should not be cut - campaigners
Disability groups have written an open letter to Work and Pensions Secretary Iain Duncan Smith, urging him to abandon planned cuts to a key benefit reports BBC News.
The House of Lords will vote next week on government plans to cut £30 a week from Employment and Support Allowance (ESA) for some new claimants from 2017.
The letter says it will make it harder for disabled people to find work.
But the Department for Work and Pensions says the campaigners are "scare-mongering".
"[The letter] fails to acknowledge that existing claimants and those with the most severe disabilities will not be affected at all," a spokesman said.
From April 2017, ministers are intending to reduce the amount of money people in one category of ESA receive, taking approximately £30 a week from new claimants who are deemed to be capable of making some effort to find work.
The change will bring the benefit rate in line with Jobseeker's Allowance.
'Closer to poverty'
More than 30 charities and members of the Disability Benefits Consortium, including Mencap, Mind and Parkinson's UK, and three peers, including Baroness Tanni Grey-Thompson, the record-breaking Paralympian, signed the open letter to Mr Duncan Smith.
The letter said the change would "push sick and disabled people further away from work and closer to poverty".
"The government says this £30 disincentivises sick and disabled people from finding work, but it has so far offered no evidence for this claim," the letter said.