THE SNP is to push ahead with plans to reduce periods of community supervision for long-term prisoners to a minimum of six months, after Justice Secretary Michael Matheson fought off challenges from MSPs and fierce criticism of academics.

The Scottish Government has said that those sentenced to four years or longer, currently released on licence two thirds of the way into their sentence and subject to recall to jail if they misbehave, should be let out of jail six months before their sentences are due to end if the parole board has ruled they are not safe to release earlier.

At a meeting of Holyrood's justice committee, Labour MSP Elaine Murray and Conservative Margaret Mitchell sought to amend the Bill which has been relentlessly attacked by academics who have warned reducing periods of controlled release will increase danger to the public by leaving insufficient time for effective reintegration.

However, both MSPs withdrew their amendments after it became apparent that they would not attract the support of a majority of committee members.

Ms Murray suggested a proportional system which had been recommended by the committee previously. Under her proposal, prisoners would serve at least 12.5 per cent of their sentences on licence.

She said that those who had served longer sentences would be likely to require more rehabilitation work in the community as a result of institutionalisation, and that the Government's plan for a six month period would apply only to the most dangerous criminals who the parole board had deemed it too dangerous to release at an earlier stage.

Ms Mitchell sought to introduce an amendment that would delay the legislation so that the issue could be re-examined, following what she called "pertinent and forensic criticisms" of a Bill she branded "not fit for purpose".

She said: "The original policy memorandum states that the Bill ends the system of automatic early release in the interests of protecting public safety. The Government proposed changes do not end automatic early release... it merely replaces automatic early release at the two thirds point with automatic early release at six months before completion.

"This has proportionality implications that may well lead to a [human rights] challenge. The Government has not made the case as to why it rejected the proportionate approach.... it does not address the risk to the public from what could be a very difficult prisoner being released.

"It's hard to work out what the Government is attempting to achieve with this Bill. The inevitable conclusion was that this was bad legislation to begin with and the Scottish Government's attempt to address stakeholders' extensive and legitimate criticisms have muddied the waters further and made things worse."

In a hot-tempered exchange, Ms Mitchell broke off from her submission and attacked SNP backbencher Roderick Campbell who she accused of laughing after she said she was introducing a probing amendment.

"I notice people are laughing at that... this is far too serious I think to be dealt with flippantly Mr Campbell," she said, before committee convenor Christine Grahame stepped in.

Mr Matheson said that the Government had responded to earlier concerns over 'cold release' and decided the six month period was appropriate as the initial 12 weeks after release had been highlighted as the most vital for effective reintegration into the community.

He said: "It's important to stress that the need for the operation of a mandatory period of licenced, conditional supervision will apply to a limited proportion of long term prisoners only. This is because many long term prisoners will continue to receive parole board early release or will have an extended sentence in place.

"Various views have been expressed about what length the minimum supervision period should be. We considered that the length of mandatory supervision should be six months. A considerable amount of work goes on inside prisons to plan for the release of prisoners... all of this is focussed on an individual prisoner's needs and is done in prison ahead of release.

"We think the minimum period of supervision necessary for a prisoner serving four years, as compared to a prisoner, say, leaving after eight years in custody, is likely to be similar. It is the initial six the twelve weeks following release that are generally most crucial for individual prisoners."