Probation officers took the corridors of Parliament by storm yesterday to demand a halt to their service’s privatisation.

Members of probation unions Napo and Unison assembled at Westminster in their hundreds to lobby MPs on the dangers of the government “reforms” dubbed Transforming Rehabilitation.

They then held a rally attended by several supporting parliamentarians including shadow justice secretary Sadiq Khan and fellow Labour MP Andy Slaughter.

“Seeing the packed room reinforced to me the overwhelming opposition by dedicated and experienced probation staff to the government’s reckless privatisation plans,” said Mr Khan.

Napo spokeswoman Tania Bassett said the rally was “an absolute success” and that the union’s “members came out reinvigorated.”

Hayes and Harlington MP John McDonnell hailed probation officers’ efforts to save the service as “impressive.”

Attendees were regaled with passionate speeches and heartfelt accounts of the consequences of privatisation on probation workers’ lives.

Former West Mercia Probation chief executive David Chantler said: “Splitting up the probation service on the basis of risk is criminally insane.”

Mr Khan said: “With morale so low, with many dedicated and experienced staff on sick leave or leaving because of this government’s reckless plans, public safety is being put at risk.”

And he added: “It’s a pity that Chris Grayling has his fingers in his ears, because this crazy privatisation needs to be stopped before it is too late.”

New figures show that 98 per cent of probation workers do not trust the Tory Justice Secretary.