It doesn't 'have zilch to do with the probation service", it's closely linked to the devastation to the Probation Service caused by the Conservatives. It's in the process of being taken back into public ownership because the attempt to privatise, ie make it into a profit making business, has failed spectacularly.
WE had a good Probation Service. One of its many roles was to work with offenders during their prison sentence. It was called "thoroughfare', I remember studying the course during my training in the late 70's early 80's.' The service had a proud history and the mantra "to advise, assist and befriend" underpinned its work.
On a separate point, we have significant problems in our prisons with radicalised groups of offenders. We have cat A prisons where some groups operate with little control. Slash and burn the criminal justice system, then blame a previous government for something it did 10 years ago.