Industrial Laundry Services Why Isn't Work Compulsory In UK Prisons? Would You Agree With It?

Why isn't work compulsory in UK prisons? Would you agree with it? - industrial laundry services

As far as I know, the work is not compulsory in British prisons, and I am sure that some prisons offer employment.
If (the work is not necessarily hard work) is compulsory, then prisons must pay for itself without public funds and at the same time, their products and services from outside the company.
I remember one work in some prisons, the laundry and industrial assembly lines of products, but do not think they are (often?)
Prisonsers keep as physically and mentally active, perhaps with less time to cause problems. In some cases, provide the skills that are useful in the outside world. Is not this a win-win?
With the growth of our prison population anyway, and the lack of jail space, it is certainly unlikely that the situation could arise in the near future in which people unjustly imprisoned by the authorities sent as a source of free hand work!