Higher reoffending rates and worse risk management will be among the real-world consequences for probation services in england and wales if the government does not increase funding in its forthcoming spending review, the head of the sectors watchdog has warned.

Justin russell, the chief inspector of probation, also said in an interview that the systemwould need extra cash because of the extra work likely to be generated by the plan to recruit20,000 new police officersin england and wales by march 2023. that programme had producedmore than 4,300 new recruits by the end of june this year.

Meanwhile, the probationbudget per service user fell 40 per cent between its peak in 2003-4 and 2018-19, mr russell said.

The former justice ministry and home office official made his plea after delivering his submission to the spending review, which will cover the early termination next june of the contracts given to private operators in 2015 to run services overseeing low and medium-risk offenders in england. mr russells predecessor, glenys stacey, criticised the part-privatisation, made when chris grayling was justice secretary, as irredeemably flawed.

All supervision of offenders in wales was transferred to the state-run national probation service last year.

The nps, which manages high-risk offenders, has largely fared well in inspections, despite some high-profile mistakes. the errors include the failure to spot that usman khan, a convicted terrorist who killed two people at fishmongers hall in central london in november last year, represented a continuing threat.

Mr russell said the poor record of the private community rehabilitation companies (crcs) had real-world consequences, including violent and property crimes that would otherwise not have occurred.

One of the worst areas of performance weve seen is around how some of these services are assessing risk of harm, mr russell said, adding that some providers were failing to do checks they needed to carry out with police and social services about offenders records.

The system had become almost like a three-tier probation service with most of the seven nps geographical areas in england and wales performing well and some of the crcs doing well but others performing very poorly. the worst-performing crcs have been starved of funding, made significant cuts in the number of people employed and replaced experienced staff with more junior employees.

Mr russell, who has been chief inspector since june 2019, declined to give a precise figure for the extra funding needed to restore the worst-performing services. but he highlighted a 2019 national audit office report said that the ministry of justice expected to pay providers 822m less over the seven-year life of their contracts than originally envisaged.

As a result, providers had been receiving about 100m less annually than the treasury intended to spend, mr russell said. the shortfall represents around 22 per cent of the value of the crcs contracts and pushed one provider working links, which held three of the 20 contracts to operate crcs in england into administration in february last year.

A shortfall of 100m a year is a big shortfall thats difficult to take, mr russell said. thats why staff numbers have been falling in these services and the big impact you see is bigger and bigger caseloads [for each officer]. that makes it very difficult to supervise people.

Mr russell said it was necessary to take account of that underspend in the governments comprehensive spending review due this year and ensure it was compensated for in future.

It was also important to factor in how the recruitment of extra police officers would result in extra arrests and convictions. that would mean more people either leaving prison under supervision or undertaking punishments such as unpaid work that probation officers oversee.

That will generate extra business for probation, mr russell said of the recruitment drive.

Andrew neilson, director of campaigns at thehowardleaguefor penal reform, a charity, welcomed mr russells warning, saying probation had long been the cinderella service of the criminal justice system.

Chris graylings botched privatisation cut costs to disastrous effect, mr neilson said. reversing those reforms was a step in the right direction but only proper investment, and a properly local and independent structure, will create an effective and creative probation service.

The ministry of justice said it had increased the probation budget by 17 per cent this year compared with last, to more than 1.1bn.

We... will ensure it continues to have the resources it needs to protect the public and reduce reoffending, it said.