Every part of economic life has jobs that no one wants to do. In offices, there are photocopier-jockeys, cleaners, and the nice bod who changes the light bulbs . In the service industries there are those who collect sanitary towel disposal units, people who serve cheap food, and people who pass you your groceries in a nicely packed bag.

What, then, is the difference between this and the equally mundane, unskilled work that prisoners are forced to do? It is a frequent bleat from prison staff that it has the benefits of inculcating the "work ethic", and that people outside also have to do dull work.

The difference should be obvious and severe. In prison, we are forced to work under threat of force. It is slave labour, and a refusal to comply leads to immediate and long lasting sanctions. We can be placed in the punishment block and deprived of "privileges" such as tobacco, books, radio, visits, clothing... It even affects our chances of release. We can be held in prison for refusing to work.

Of course, not working in the outside world has inherent sanctions, loss of income being one. But there is a huge difference between getting slapped by the anonymous hand of a capitalist market and being produced in front of a Governor who reads off a list of the privations that he is imposing on you. That is a deliberate and personal exchange, not the hidden hand of market forces. And ultimately, refusing to work in the outside world is possible; it is not an offence in itself against the state, even if society would feel insulted. Prison work is forced labour, a deliberate and personal policy decision.

Low-quality work in the outside world is not a fixed entity. The flexibility of the market, coupled with the individual qualities of the worker, allow for progression. The poorest quality work is a starting position and the possibilities are endless. Progression is possible, even probable.

For prisoners, the low quality work is the pinnacle of his experience. The work we are forced to do today is exactly the same as the work we were forced to do 30 years ago. No matter what effort the prisoner makes, no matter what abilities or advancements he makes in his qualifications, he is forced to sit at the same work bench year after year. Low quality work in this position isn't the starting position; it is all that is made available as a matter of deliberate policy.

The relationship between the employer and worker can be a complicated one, but in the free world it ends with the completion of the working day. For prisoners, the employer decides his hours of work, his rate of pay, then determines how he can spend that money and regulates his leisure time. These are the hallmarks of slave labour. It is a relationship between the powerful and the powerless.

This reveals the idea that prison work somehow fosters a work ethic to be a chimera. A fair day's pay for a fair day's work, with liberty at the end of the working day, and the potential for economic and social advancement - these are the hallmarks of the work ethic. None apply to the prisoner, and to make such a claim is to wallow in obtuseness or to deliver a deliberate insult.

The benefits of the free man's labours are divided with the employer - usually to the worker's disadvantage. This unfairness pales into insignificance when compared to the iniquity foisted onto the prisoner. The rise of "contract services" in prisons has seen the civilian employer take advantage of slave labour in new ways. Whereas prisoners were previously forced to produce goods largely for the internal Prison Service markets, contract services allows outside employers to subcontract work to the prison - who forces it onto prisoners. The prison takes the bulk of the payment from the employer, and passes the residue on to the prisoners. A wage rate of 50p an hour is a very good prison wage. The benefits to employers are obvious - a workforce who cannot refuse to do the work, and who are paid pocket money. I believe this method of work was pioneered by Albert Speer.

The results of these circumstances are obvious. The civilian employers benefit hugely by having a captive, compliant and pitifully cheap workforce, increasing their profits beyond anything they could achieve without forced labour. The Prison Service benefits, in gaining an income from civilian employers. It helps individual Governors to meet internal targets for having prisoners out of their cells and in "purposeful activity". Prison staff benefit, because when prisoners are off the wings they can feed their crossword and sudoku obsessions in peace and quiet.

And the prisoners, who provide the human fuel, the engine for all of this activity? They enter prison and are stripped of all their economic and social capital. They leave, maybe decades later, with beer-money and having learned only what it is to live under tyranny.

Prison work is a deliberate and wilful insult to all that it means to be an autonomous human being. It bears all of the hallmarks of slave labour, and in attempting to give it any patina of respectability both the Prison Service and employers collude in a shameful enterprise that cheats the taxpayer and enslaves the people in their domain.