Thousands of criminals who are sentenced to community service are escaping full punishment, Conservative leader Ruth Davidson has warned.
Community Payback Orders (CPOs) were introduced by the Scottish Government in 2011, giving sheriffs the ability to send low-level offenders out into the community to pay back for their crimes through work.
Ms Davidson challenged the effectiveness of the policy during First Minister's Questions at Holyrood.
She said the Government's own justice figures revealed that during 2011/12 more than 10,000 CPOs were handed out, of which 7,763 involved an element of unpaid work. Of these, less than a third - 2,536 - were completed.
The statistics also reveal that more than 2,600 of the 7,763 orders were officially terminated last year, with about a third of these signed off although not completed by the offender.
The Tory leader cited the concerns of Sheriff Graham Buchanan, who was recently quoted as saying the public would be "horrified" by the way the orders were being administered.
Ms Davidson said: "There is a massive backlog, whole sentences are signed off only partially completed and offenders are credited with work they never do. Communities are being conned and not paid back. Is that why on Monday this Scottish Government advertised for an outside body to evaluate whether CPOs are working at all?"
First Minister Alex Salmond said the Government was making "good progress on CPOs".
He said: "We evaluate policies because we welcome that sort of independent scrutiny of the success of the policies. We look - outside body or not - in terms of justice, very carefully, at the success of the policies."
He said the reconviction rate had dropped to its lowest level for the last 13 years, which is an important factor in relation to sentencing.