The spectre of the chain gang and the abused "tickey-a-day" farm labour is again stalking South Africa. It arose this week, following the announcement by the Democratic Alliance (DA) of its "criminal justice plan", which has attracted widespread condemnation, particularly in the labour movement.

Speaking in Johannesburg on Tuesday alongside DA leader Helen Zille, the party's correctional services spokesperson, James Selfe, announced the planned introduction of "productive labour" for prisoners.

Convicts should be made to "earn their keep", he reportedly said.

"At a time of mass unemployment and wage cutting, this is totally unacceptable," said Dennis George, the general secretary of the Federation of Unions of SA. "Prisoners should be educated and reskilled as part of a rehabilitation process."

This view was echoed by both Cosatu and the National Council of Trade Unions (Nactu), with the latter dismissing the DA proposal as "a cheap pre-election gimmick".

Patrick Craven, the Cosatu spokesperson, said: "We need skills training and rehabilitation, not the use of forced labour to deprive workers of jobs."

The Police and Prisons Civil Rights Union (Popcru) saw the DA proposal as a move closer to the prison labour system that was adopted in the US. "So we strongly condemn any such plan," said spokesperson Benzi ka-Soko.

Popcru is considering legal action against the country's two privatised prisons, in Bloemfontein and Polokwane, where the union has been recruiting prison staff. The objective is to bring the prisons back to the public sector's control and away from what is seen as the profit-driven example of the US.

The US experience was highlighted in this column nine years ago, when the Bloemfontein and Polokwane prisons were being built. It was summed up then in an interview with US writer and film producer Eve Goldberg.

She gave the example of an American garment worker, once paid an hourly rate of $8, who loses his job when work is outsourced to Thailand to workers paid $2 a day.

Goldberg noted: "Unemployed, alienated from a society indifferent to his needs, he becomes involved in the drug economy or some other outlawed means of survival. He is arrested, put in prison and put to work. His new salary: 22 cents an hour."

Companies with well-known brand names were quick to take advantage of this cheap labour. Work returned to the US, but in conditions of slavery.

Research by leading US criminologist professor Randall Sheldon has shown that prisoners in these circumstances tend to be kept in jail longer, often for minor infractions of prison rules, apparently because of the profit they generate. Inmate labour is now a major industry in the US.

Manene Samela, the Nactu general secretary, said: "That's precisely the route we do not want to go. This again avoids dealing with the causes of crime. We need to change mind-sets through skilling and education."

Cape Town medical doctor and prison reform campaigner Judith van Heerden was outraged by the DA proposal, saying: "This leads to a workhouse situation, where the prison authorities can do as they please with prisoners."

She maintains that almost no rehabilitation now takes place in our prisons and that most inmates become "more and more brutalised". She said: "This workhouse proposal is no solution … People who go into prison invariably emerge more damaged and violent than when they went in."

The unions agree that the proposed plan will merely exacerbate the situation.