The Campaign Against Prison Slavery (CAPS) was formed in 2002 by ex-prisoners, prisoner support groups and activists to campaign against compulsory labour in UK prisons and for the abolition of the Incentives and Earned Privileges Scheme (IEP).

Compulsory labour is a feature of most prison systems a round the world, whether it be forced hard labour as punishment, direct 'reparation' for the costs of imprisonment, prison jobs such as kitchen or cleaning work that keep administration costs down or workshop jobs where prisoners manufacture the cell doors and prison bars for the jails that house them.

However, the modern prison has also developed into a system for generating capital from a section of society that up until now has largely been held to have no intrinsic labour value, the marginalised elements that tend to be trapped on a roundabout of regular incarceration, never to hold down a 'proper' job or become a 'productive member of society'. Thus we now also have in the modern prison system the prisoners who are used to create capital for private sector companies, either through labour in prison workshops manufacturing and packing goods for these companies or those prisoners handed over wholesale to the global outsourcing and security companies that run the private prisons, to do with as they wish, often 'sub-contracting' them out to third party companies.

1. For the purposes of this Convention the term "forced or compulsory labour" shall mean all work or service which is exacted from any person under the menace of any penalty and for which the said person has not offered himself voluntarily.

2. Nevertheless, for the purposes of this Convention the term "forced or compulsory labour" shall not include:
c ) Any work or service exacted from any person as a consequence of a conviction in a court of law, provided that the said work or service is carried out under the supervision and control of a public authority and that the said person is not hired to or placed at the disposal of private individuals, companies or associations.