Tens of thousands of the most vulnerable patients are effectively being kept prisoner in care homes and hospitals through misuse of mental health laws, a damning House of Lords investigation has found.
In the worst cases safeguards aimed at protecting patients with a wide-range of conditions are being used to " oppress " people and force decisions on them, peers said.
They found measures that are supposed to be used to look after at-risk patients, such as people with dementia who might get lost if they leave their care home, are being used on a significant scale to wrongly deprive them of their liberty.
The House of Lords committee set up to investigate how mental health reforms introduced in 2005 are working said it was so concerned about deprivation of liberty safeguards that they should be scrapped and a new system drawn up from scratch.
Committee chairman Lord Hardie said: " We were very concerned by what we heard about the safeguards. The evidence suggests that tens of thousands of people are being deprived of their liberty without the protection of the law, and without the protection that Parliament intended.
"Worse still, in some cases the safeguards are being wilfully used to oppress individuals and to force decisions upon them, regardless of what actions may be in their best interests.
"The criticism of the safeguards extended to the legislative provisions themselves; we were told the provisions were poorly drafted, overly complex and bureaucratic. A senior judge described the experience of trying to write a judgment on the safeguards as feeling "as if you have been in a washing machine and spin dryer". Even if implementation could be improved, the legislation itself is flawed.
"In the face of such criticism, the only option is to start again. The Government needs to go back to the drawing board to draft replacement provisions that are easy to understand and implement, and in keeping with the style and ethos of the Mental Capacity Act."
The report highlights the case of Steven Neary, a man in his early 20s with autism and a severe learning disability, whose father asked Hillingdon Council to provide some short-term respite care.
It said staff found Steven's behaviour very challenging and were concerned about his return home and it was agreed he would stay in care for a couple of weeks.
The report adds: "In fact, the council had already decided that Steven should not be allowed to return home and kept him at the facility for nearly a year, including a period when he was subject to the deprivation of liberty safeguards. During this time plans were made to send Steven to live permanently at a facility in Wales. The Court of Protection held that Steven had been unlawfully detained and ordered that he must return home to live with his father."
The safeguards are part of the wider Mental Capacity Act drawn up to simplify how patients who lack capacity are dealt with and to "empower, protect and support" them.
Peers found there has been "patchy" take-up of the measures it contains and called for the creation of a single independent organisation to take responsibility for implementation.
Lord Hardie said: "When the Act came into being, it was seen as a visionary piece of legislation, which marked a turning point in the rights of vulnerable people; those with learning difficulties, dementia, brain injuries or temporary impairment. The committee is unanimous that this is important legislation, with the potential to transform lives.
"However, what is clear from the substantial volume of evidence we have received is that the Act is not working at all well. That is because people do not know about the Act, or do not understand it, even though many professionals have legal obligations under it. Those who may lack capacity have legal rights under the Act, but they are not being fulfilled. In many cases complying with the Act is treated like an optional add-on - nice to have, but not essential. In short, the Act is not being implemented.
"The committee believes that the Act is good and it needs to be implemented. What we want to see is a change in attitudes and practice across the health and social care sector which reflects the empowering ethos of the Act."