The National Autistic Society has questioned the record of the company chosen to carry out new assessments for disabled people.
Amanda Batten from NAS said the government’s decision to use Atos as one of the providers of oversee Personal Independence Payments is "highly surprising".
It was announced that Capita would also carry out the assessments on up to two million people who currently get Disability Living Allowance.
"This week we saw two television programmes suggesting that the company had been granting benefit based on an arbitrary limit rather than the very real needs of disabled people," she said.
"Since the Work Capability Assessment (WCA) delivered by Atos failed to take into account the needs of so many people with autism and other disabilities there will be real concerns in the community about this decision.
"The government must ensure that Atos and Capita learn from the failings of the WCA, which has not only wasted money but caused untold distress for many thousands of legitimately disabled people."
Ms Batten described PIP as "the government’s last chance to honour their promise to help those who need it most".
She added: "The introduction of PIP must be a genuine strategy to improve the current system and not simply a money saving exercise. We all want to see a system that works well and protects people with autism and other disabilities who genuinely need help."