A major review has concluded there is little evidence to suggest a key plank of government plans to toughen up mental health laws actually works.
The plans have proved controversial
The Mental Health Bill would allow for compulsory treatment of people with a range of psychiatric disorders in the community.
But the Institute of Psychiatry review found no evidence from other countries of community treatments orders' worth.
The government rejected accusations the review had been buried.
Doctors have used a "treatability test" since the mid 20th century to decide if someone should be detained.
It has been the practice that people with personality disorders have not been detained because their condition cannot be treated. But the government now says they can be detained and given some kind of therapy.
Tim Loughton, the shadow health minister, said ministers had had access to the conclusions of the review for six months, but had chosen not to release them while the Bill was being debated by the House of Lords.
He said: "The government are guilty of disgraceful manipulation in regard to the timing of the publication of this report."
No robust evidence
The Department of Health dismissed this as "absolute nonsense".
A spokesperson said a final, peer-reviewed copy of the report had only been received less than three weeks before it was made public.
The plans have proved controversial, and the Lords last month voted for a series of amendments placing restrictions on the use of CTOs.
The report, which examined 72 studies into the use of CTOs in six countries, found it was not possible to state they were beneficial or harmful to patients.
It concluded: "Overall, although some stakeholder views are positive, there is currently no robust evidence about either the positive or negative effects of CTOs on key outcomes, including hospital readmission, length of hospital stay, improved medication compliance, or patients' quality of life."
The Department of Health said there had been positive reports about the effect of CTOs from New Zealand, Australia, US and Scotland.
A spokesperson said: "Community treatment orders (CTOs) are a key part of helping to solve the problem of 'revolving door' patients.
"We know that many tragedies in mental health are preceded by non-compliance with treatment and CTOs will address this."
However, Professor Louis Appleby, the government's National Director of Mental Health, announced on Wednesday that Oxford University would carry out further research into how CTOs will work in practice.
Paul Farmer, chief executive of mental health charity Mind, said the government plans were "fundamentally flawed".
He said: "Community treatment orders won't help people at all.
"They do not improve compliance with medication. They do not lower incidents of violence or arrest. They do not reduce length of stays in hospital. They do not prevent re-admissions. "But they will scare vulnerable people away from seeking help when they need it."
Rowena Daw, of the Mental Health Alliance, said: "We call on the government to use the evidence its own research has provided and to listen to the professionals, patients and families who have expressed such strong concerns about CTOs.
"We agree with government that compulsory treatment in the community can help a small number of people in very specific situations, but the current plans go too far.
"They will not limit the use of CTOs to this small group of people and they will place unnecessary restrictions on people's daily lives."
Marjorie Wallace, chief executive of the mental health charity Sane, said: "Our concern remains that community treatment orders could be used as an excuse to deny essential in-patient care to people who need it, while the government's agenda is reducing the numbers of psychiatric beds and days in hospital."