Thousands of offenders are to be given a second chance to prove they can change their ways before being sentenced by the courts.

Ministers plan to roll out a pilot project today which offers those convicted of low-level crimes, including breach of the peace and minor assault, three to six months to engage with addiction and employment services to avoid being sent to prison.

Kenny MacAskill, Scottish Justice Secretary, is expected to announce that the scheme, which has already been piloted in Arbroath, Forfar, Inverness, Ayr and Kilmarnock, will be extended to Glasgow and Tayside. The aim is to try to curb re-offending and ease pressure on Scotland's burgeoning prison population.

Structured De-ferred Sentence (SDS) gives offenders the opportunity to take part in specific programmes after conviction and prior to sentencing.

During sessions with social work staff and other professionals, offenders are made to look at issues around their criminal behaviour. Recommendations for SDS will be made by social workers in the social inquiry reports they compile for sheriffs.

The scheme targets the underlying causes of crime such as drug or alcohol dependency, mental health problems and unemployment.

At the end of the programme, which is normally after three months, the person returns to court for sentencing when their involvement in the sessions is taken into account by the sheriff.

Those who engage with the process are far less likely to be given a custodial sentence and in most of the pilot areas, the most common sentence given at the end of the deferred period was admonishment.

In Glasgow and Tayside, it will focus on more than 2000 persistent young offenders aged from 16 to 21.

"It is about giving people a second chance and an opportunity to engage with challenging their behaviour," said Doreen Peat, chief officer of Tayside's Criminal Justice Authority.

"We want to support them to change their behaviour and make them face up to the harm they may have caused other people. It is about looking at the outcome most likely to reduce their reoffending."

The evaluation of the pilots, which began in 2005, revealed that sheriffs had confidence in the scheme and its potential to reduce re-offending. They were positive about the greater level of control afforded by seeing offenders again after three months.

The report said the initial uptake by the courts was lower than anticipated which had a knock-on effect on cost but overall the expense was about the same as probation or a community service order. Roughly one fifth of orders were not completed, lower than community service.

However, there were concerns raised about the fact that failure to engage with the orders did not, unlike a community service order, lead to the offender being referred straight back to court.

Under SDS, any breaches of the deferred order such as non-attendance are dealt with when the offender returns to court after the three-month period.

Mr MacAskill is expected to announce funding of £667,000 per year for the next three years for the scheme.

"Structured Deferred Sentences offer the courts a highly credible option for providing formal interventions with low-level offenders," he said.

"These sentences target people who would benefit from social-work led supervision that targets the underlying causes of their offending behaviour. We are not talking about violent, serious and dangerous offenders.

"A crucial aspect of changing criminal behaviour is demonstrating that there is a more rewarding alternative to a life of crime. Short prison sentences often fail to deliver on that goal.

"These types of interventions can help an offender address underlying problems, improve employment prospects and build a sense of routine and self-esteem. This can lead to a future which is free from offending - and that is what we all want."

James Maybee, principal officer with social works services at Highland, said the pilot in Inverness had already proven to be successful.

"Like the diversion from prosecution scheme, there is a really positive incentive for the offender to take part," he said. "That motivational tool has had a really positive impact.

"Before the pilot began, the courts could always defer sentence for good behaviour for six or 12 months but there would be no intervention in the meantime and the only report back to the sheriff would be whether or not the person had re-offended in the meantime. The structured aspect of this means we are engaging with the problems which may be underlying their offending, including addiction, housing and employment.

"It means we can go back to the court three months later and say they have stabilised their drug taking or found stable accommodation."