Inspectors found staff assigned to manage low and medium-risk individuals in Gloucestershire were making "heroic efforts" but faced "plainly unreasonable" caseloads.

The report, authored by HM Chief Inspector of Probation Glenys Stacey, said a community rehabilitation company (CRC) in the county owned by Aurelius/Working Links was "poor."

Dame Glenys said "plans were not being followed through anywhere near well enough and some offenders were not being seen often enough."

In several cases, the CRC had lost contact with an offender for "significant periods."

One man convicted of assault was said to have had no contact for two months after his first officer left.

The CRC is just the latest privatised probation operator to be damned by inspectors. A controversial shake-up of the system handed all but the most high-risk offenders to outsourcing giants.

Probation union Napo general secretary Ian Lawrence said the report was "further proof" that his union’s warnings over the impact of privatisation "have proven to be correct."

He said there were now "serious questions" over the whether the company "ought to be stripped of its contract."

Dame Glenys added: "This CRC's work is so far below par that its owner and government need to work together urgently to improve matters."

A spokesman for the CRC said it was acting on the report’s recommendations and Dame Glenys had "highlighted many pieces of good practice as we work hard to combat reoffending."

Shadow justice secretary Richard Burgon said: "The Tories were repeatedly warned that their reckless part-privatisation of probation would prove to be a costly disaster."