The Independent on Sunday today urges all MPs to read the story of one child's treatment under Britain's current outdated and draconian mental health laws.

Jack Owen was just 16 when he was sexually assaulted by a male patient, verbally abused and locked up in a windowless cell on an adult psychiatric ward. His story, told here for the first time, is a damning indictment of Britain's mental health service.

Tomorrow, the Government will attempt to force through its mental health reforms - reforms that this newspaper opposes and which experts warn ignore the care and treatment needs of thousands of vulnerable children like Jack.

The IoS has been campaigning for nearly five years for the rights of people with mental health problems to be respected. The campaign has been backed by leading medical and psychiatric experts as well as figures from politics, the media and the arts. Lord Bragg described the campaign as: "Useful, important and corrective. There have been an awful lot of injustices and an awful lot of neglect. Exposing what is going on is very important.

Now we are calling on MPs to accept a series of amendments put forward by the House of Lords, which psychiatrists, mental health charities and patients have said would help to create laws fit for the 21st century.

These include the demand that children be treated in wards suitable for their age, not with adults, and be assessed by specially trained professionals.

Today we also publish figures from the charity Young Minds which expose the "national scandal" of how children as young as 12 are incarcerated with often extremely disturbed adults and end up more traumatised than when they went in for treatment.

The study found that one child every day is admitted to an adult mental health ward under section; that more than three-quarters of girls are detained on mixed-sex wards; that the average stay is at least one month; and that children face a postcode lottery over beds.

Kathryn Pugh, head of policy at YoungMinds said: "Unless changes are made in the law, children will continue to be at risk, and their chances of recovery seriously jeopardised."

Critics are warning that the Government is risking a damaging and drawn-out battle over the Bill because it is not prepared to listen to the combined expertise of mental health professionals, peers and patients.

Ministers have insisted it is necessary to get people with severe disorders off the streets, even if there is no treatment available. This has been a major source of opposition - especially from psychiatrists, who believe they will be turned into jailers.

The Lords are demanding that only people with conditions that can be treated should be sectioned and placed in mental hospitals. They also want to water down the use of community treatment orders, dubbed "psychiatric Asbos", so that their use is restricted to patients who have a history of refusing medication.

But it is understood that the Government is not prepared to make any concessions and has put Labour MPs on a three-line whip in an attempt to bulldoze the Bill through.

As a result, the Tories plan to hold their own special committee hearing next week on the Bill so that patients and campaigners get the opportunity to voice their concerns in public.

Tim Loughton, the Conservative health spokesman, said the input of experts had led to an improved Bill and it was crucial that their amendments were upheld. He said: "It looks as though the Government has not learned the lessons and will be attempting to bulldoze through a Bill which is all about turning professionals into jailers."

Norman Lamb, the Liberal Democrat health spokesman, said: "If the Government drives its original Bill through Parliament without these changes, it would be insane and a disaster."

Andy Bell, chair of the Mental Health Alliance, said what the Government was proposing was "unnecessary, pointless and outdated".