Uncosted Con-Dem plans to hand responsibility for "violent criminals" to scandal-hit security privateers were banged to rights by opposition MPs in Parliament yesterday.

Another step was expected to be taken towards selling off 70 per cent of Britain's probation service as the Offender Rehabilitation Bill reached its second reading.

But not before Labour MPs and Plaid Cymru MP Elfyn Llwyd, the chairman of Parliament's justice union group, exposed the dangers posed to public safety by privatisation.

They quizzed Justice Secretary Chris Grayling on why he had not costed or piloted his plan to hand over responsibility for low and medium-risk offenders.

Their amendment also revealed that his department's own risk register states there is a high risk of service standards slipping.

Labour shadow justice secretary Sadiq Khan called the privatisation a "massive leap into the dark."

He said: "Experts, probation staff and management and MPs from all side have warned the abolition of the Probation Service and handing over serious and violent criminals to the likes of G4S and Serco will put the safety of communities up and down the country at risk."

Britain's 35 "good" or "excellent" rated probation trusts will be scrapped next March, with a husk public service remaining to rehabilitate high-risk offenders.

Mr Llwyd said that would see responsibility for between 70,000 and 140,000 offenders convicted of violent or sexual offences outsourced to contractors.

And he warned they will be "companies who have a perverse incentive to allow reoffending to increase so that they can increase their profit margin."

He added the "drastic changes" have thrown the lives of 18,000 staff into unceartainty.

"There is a real risk that many of the best staff will leave the profession," he warned.

Mr Grayling tried to divert attention from privatisation by claiming that his Bill helped offenders who serve less than 12 months in prison.

He said they are currently released "with £46 pounds in their pocket and with little or no support at all."

Mr Khan said Labour supported extended supervision but had "no confidence" that privateers could implement the changes.