Community sentences to be 'toughened up' for offenders
Ministers are to set out plans later for tougher community sentences for offenders in England and Wales.
The plans could include wider use of electronic tagging using GPS tracking and intensive punishment orders including curfews and travel bans.
Around 170,000 people a year are given community sentences, but ministers are concerned they are too lenient.
Probation union Napo said tougher sentences may see more offenders fail to meet their requirements.
The Ministry of Justice (MoJ) says trials show community sentences are cheaper and cut re-offending.
It says the aim is not necessarily to reduce the numbers in prisons, but the new community sentences could allow courts to impose fewer sentences of less than 12 months.
They are often thought to do more harm than good when it comes to preventing reoffending.
The latest Global Positioning System tagging devices, which are currently being trialled, would be used to enforce restrictions on an offender's movements.
Justice Secretary Kenneth Clarke will set out the proposals later.
"We are overhauling community sentences to ensure they are tough, credible and robust," he will say.
"Criminals must be punished for their crimes, they must pay back to communities and victims for their crimes and they must be reformed.
"If we can get criminals to return to a law-abiding way of life, we stop them committing more crime against more victims."
He will also set out plans to "modernise" the probation service "so that we bring in more of the energy and innovation of the widest possible range of providers to bear on the battle against reoffending and crime".
"Good sentencing is a combination of firm punishment and effective reform of the offender," he will say.
But probation union Napo voiced concern about a negative impact of tougher community sentences.
Assistant general secretary Harry Fletcher said: "The more punitive the order is made by government, the higher the breach rate."
Mr Fletcher also said there was "no evidence that GPS satellite tracking will reduce crime or save costs".
"It is based on technology similar to mobile phones and it is highly likely that there will be hundreds, if not thousands, of alleged breaches every day when signals cut out," he added.
"There have been numerous attempts by successive governments to toughen up community supervision. All have failed and resulted in high breach rates and, therefore, more imprisonment."