The Mental Health Bill attempted to do two almost contradictory things and ended up proving impossible to manage.

The government was first prompted to introduce new legislation after the conviction of Michael Stone for the brutal murder of Lin and Megan Russell in 1998.

Stone was revealed as a known and dangerous psychopath but a "loophole" in the law as it stood meant he could not be detained under the Mental Health Act.

The problem was that the Act only applied to those would be "treated" for their condition and psychiatrists had long maintained that personality disorders were not treatable.

"We are doctors not gaolers", it was argued.

So one central and controversial aim of the new bill was to change the definition of "treatable" allowing psychopaths and those with personality disorders to be "sectioned".

But the proposals had another ambition - to ensure that England's mental health legislation complied with the Human Rights Act.

This meant putting in safeguards so that anyone detained could challenge their incarceration with access to an advocate and a tribunal.

Bill 'abandoned'

However, when the proposals were examined, fears grew that they might create a huge and expensive bureaucracy which would divert scarce mental health resources away from the front-line.

After eight years, millions of pounds, an expert committee, a Green paper, widespread consultation, a White paper, two draft Bills and formal parliamentary scrutiny process, the long-awaited Mental Health Bill has been abandoned.

Its 450 clauses simply made it too unwieldy and ministers realised they would never find the time to get it through.

Plan B is what they are calling a "streamlined" Bill which will amend the existing 1983 Mental Health Act.

However, the new proposals look little less controversial than the main sticking points in the ill-fated Bill.

'Appropriate' versus 'effective'

The proposal that personality disorders should be included within the new definition of "treatable" remains.

Professor Louis Appleby, the government's mental health czar, insists that "appropriate treatment should be made available" to such people and in certain cases they should be detained in order to receive it.

But what is appropriate?

Accepting that personality disorders are extremely difficult to treat, progress is often very slow and improvements marginal, Professor Appleby has said that certain group and cognitive therapies have been shown to have value.

Mental health campaigners, however, fear that "appropriate" may not be the same as "effective" and that any treatment offered might be used as a smoke-screen to give the authorities power to detain people who have committed no crime.

Another controversial element in the new proposals is a new community treatment order which would mean people who had been previously detained in a mental hospital but are now in the community can be forced to take their medication.

If a former patient refuses to take their drugs they can, as a last resort, be taken to some clinical setting and be forcibly injected.

While accepting that this can be of benefit to the individual, campaigners insist there must be a proper system of appeal in place to safeguard people's rights.

And this is where the Human Rights Act may come in.

Timetable

Some mental health charities think the safeguards fall short of what is required.

All patients detained will have the power to appeal to a tribunal within 14 days but campaigners argue that there should be an automatic hearing for anyone held for up to 28 days - even if the patient does not request it.

Already some are suggesting that without this mandatory tribunal the proposals will be challenged in the courts under the Human Rights Act.

Government ministers still say they are trying, as promised in the Queen's Speech, to bring in the legislation this parliament.

However, they now routinely add the phrase "if parliamentary time allows".

Given the history of the now defunct Mental Health Bill, few are holding their breath.