I was shocked by the Baby P case: the mistakes, the denials, the fact that it had all happened before and, despite claims to the contrary, that previous lessons had not been learnt.

Now I’m shocked all over again at the outcry over the prison sentence given to Baby P’s mother. This wretched young woman has been given an indeterminate sentence “for public protection” with a minimum term of five years. This means that she has to serve five years, less the time she has already been in prison, before she can be considered for parole. There is no question of an automatic release. The independent parole board has to be satisfied that her continued detention is no longer necessary to protect the public.

Two children’s charities, the NSPCC and Kidscape, have complained that the prison sentence for Baby P’s mother is inadequate. The NSPCC said: “For the sake of Peter, and for the sake of children who are alive today and whose care teeters on the brink, this case should be referred to the Court of Appeal without delay.”

I can’t understand how giving Baby P’s mother a longer sentence has anything to do with improving the life chances of other children “whose care teeters on the brink”. Presumably the NSPCC believe that a longer prison sentence would be a deterrent to other negligent mothers.

No, rather than want a longer sentence for Baby P’s mother, I want to know why she is in prison at all. It can’t be to protect the public; it can only be to punish her and/or to rehabilitate her. Sadly, prisons do not have a very good track record when it comes to rehabilitating people. Removed from society, inmates usually emerge thoroughly institutionalised, dependent and less able to make decisions and cope with life’s complexities than they were before their incarceration.

So what do you think prison is for? I’d better declare my interest: I’m vice-chair of Prisoners’ Education Trust, a small charity that believes that offering prisoners access to education improves their self-esteem and enables them to choose a more constructive way of life, thereby making it less likely that they will reoffend. I very much hope that Baby P’s mother will apply to us for a grant but this may be a forlorn hope - prison is not by any stretch of the imagination a learning-friendly environment.