Families of victims of the Winterbourne View scandal have written to the Prime Minister demanding he shuts outdated care home institutions.
In an open letter they express "anger" at the "painfully slow lack of change" five years after abuse at the former private hospital near Bristol was exposed in an undercover BBC Panorama documentary.
A recent report revealed that some 3,500 vulnerable people with learning disabilities are still languishing at inpatient units despite a Government pledge to close them in the wake of the Winterbourne View scandal.
Now five years after the documentary was broadcast, families of some of the victims are demanding action.
They wrote: "Dear Prime Minister,
"We the families of people abused at Winterbourne View hospital write to express our anger at the lack of change five years on from the day that Panorama exposed what happened to our loved ones.
"Despite clear commitments and plans from Government and the NHS, today, around 3,500 people, including over 160 children, are still stuck in places like Winterbourne View; often hundreds of miles from home, and at risk of abuse. Lives have even been lost.
"The rate of change has been painfully slow, and people with a learning disability and their families continue to suffer as a result. Government and the NHS must end this outdated model of hospital care and tackle the inappropriate use of restraint, seclusion and anti-psychotic medication, which is devastating lives."
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: "It was only when we were visited by two of the Panorama team that I learned of what had happened to Simon and fellow residents of Winterbourne View.
"They told us Simon had been subjected to abuse and they had footage and documentary evidence to prove it.
"I'll always remember seeing the footage - the disbelief. I was utterly speechless to see the cruelty, the physical abuse, the mental torture and the systematic nature of it all.
"Five years on Simon is thankfully doing a lot better. He is living in his own house and has become a central part of his community.
"Simon is now safe and living a full and happy life. All this, and his package of care now costs about half as much as it did when he was at Winterbourne View.
"I am devastated that five years on from Winterbourne View people with a learning disability are still stuck in inpatient units like Simon was, and families are still forced to battle a system of care that is outdated.
"It breaks my heart every time I see a photo of someone who is shut away, far from home or hear the distressed voice of a parent.
"After everything that Simon went through, after all the things that have been said by those in power, it is unforgivable that things have not changed for so many people."
Meanwhile, figures from the Learning Disability Census 2015 revealed that of the 3,000 patients receiving inpatient care who were included in the census:
:: 72% had received antipsychotic medication, yet only 28.5% were recorded as having a psychotic disorder.
:: 1,670 had experienced one or more incidents (self-harm, accidents, physical assault, restraint or seclusion) in the three months prior to census.
:: Average length of stay in an institution is 4.9 years.
:: 670 people are 100km (62 miles)or more from home, an increase of 17% on last year.
Ms Tregelles and Ms Cooper said people with learning disabilities and their families had "endured nearly five years of failure" by the authorities.
"Despite all the promises, reports and action plans since Winterbourne View, the number of people with a learning disability in inpatient units has not changed, and it is appalling that the number of children in these places has increased over the last year," they said.
"Many of these are far from home at increased risk of abuse and neglect, with their families still fighting to bring loved ones home.
"NHS England recently announced a three-year closure programme. This means that the right community-based support should be being developed for people with a learning disability and behaviour that challenges.
"But it means nothing until families see change on the ground.
"It is vital there is action now for the people currently stuck in these units, and those who are being inappropriately medicated and restrained.
"The Panorama expose of Winterbourne View created a rare opportunity to focus attention on tackling these outdated services, which are failing people with a learning disability and their families and to get care right.
"We cannot, must not, waste any more time."
An NHS England spokeswoman said: "We have seen significant increases in the numbers of people both being discharged from hospital and having their care and treatment reviewed in the last year.
"We know, however, that progress up to now hasn't been quick enough and we sympathise with the frustrations expressed.
"The real difference will be made over the coming months and years as local areas implement their response to the far-reaching plans set out by NHS England and its national partners, ensuring that the housing, care and advocacy services become available in each community to provide the high-quality alternatives to hospital people and their families want and need."