Families of victims of the Winterbourne View scandal have written to the prime minister demanding he shuts outdated care home institutions.
They said there is “painfully slow lack of change”, five years after abuse at the former private hospital near Bristol was exposed by BBC Panorama.
Some 3,500 vulnerable people with learning disabilities are still resident at inpatient units.
NHS England admits it is still taking too long to review their care.
Undercover filming showed people with learning disabilities and autism being taunted, bullied and abused at the now closed Winterbourne View Hospital.
In an open letter to David Cameron, the families of some of the victims, say that promises to close all other similar units and provide more appropriate support have not been met.
They wrote to express their anger at the “lack of change” since the revelations were made.
It added despite “clear commitments” from the government and the NHS some 3,500 people, including more than 160 children… “are still stuck with places like Winterbourne View”
The letter has been signed by Steve Sollars, Ann Earley, Wendy Fiander and Claire and Emma Garrod, whose family members were all residents at Winterbourne View.
It is supported by Dr Margaret Flynn, the author of the Winterbourne View serious case review, Jan Tregelles, chief executive of Mencap and Vivien Cooper, chief executive of The Challenging Behaviour Foundation.
Ann Earley, whose son Simon Tovey was abused at the hospital, said the first she knew about what happened to Simon, and other residents of Winterbourne View was when she was shown footage of the abuse by Panorama producers.
“I was utterly speechless to see the cruelty, the physical abuse, the mental torture and the systematic nature of it all,” she said.
NHS England acknowledged the the progress to date “hasn’t been quick enough” and it “sympathised with the frustrations expressed” but a spokeswoman said a “real difference” would be seen over the coming months.