Row over Prescoed prisoners paid £3 a day at call centre
A union has criticised a firm for "bussing" inmates from a Monmouthshire prison and paying them £3 a day at its call centre.
Unite accused Cardiff solar panel firm Becoming Green of "Dickensian" exploitation.
Both the Prison Service and the firm denied claims workers lost jobs to make way for inmates from HMP Prescoed.
Becoming Green also said a "significant amount" of wages went to victim support.
It said it was "proud" to support prisoners' rehabilitation.
The row broke out over union claims of cheap labour - and the 40-day training period, when the prisoners are paid a £15 a week food allowance.
Andy Richards, Unite Wales secretary, said: "This looks likes a disgraceful and worrying development which follows the UK government's already discredited Workfare scheme.
"It is nothing short of Dickensian to exploit prisoners by paying them just £3 a day while Cardiff call centre workers lose their jobs.
"This company seems to be all too readily taking advantage of cheap labour.
"Not only is it fundamentally immoral but it's bad for the Welsh workforce and damaging to the Welsh economy."
Steve Gillan, general secretary of the Prison Officers' Association (POA), said that for any company to rely on cheap labour of prisoners was "immoral".
"Some employers must be rubbing their hands and the shareholders laughing all the way to the bank."
But a Prison Service spokesman said: "Prison Service rules are very clear: prisoners employed by outside companies cannot replace existing staff. They can only fill genuinely vacant posts.
"Becoming Green have made it clear that the prisoners they employ are filling genuinely vacant posts and that no serving members of staff have been made redundant to make way for prisoners."
The service said the scheme employing workers at Becoming Green started in November 2011, when the company employed about 100 people.
In a statement it outlined:
- The company employs more than 190 people, of which 23 are prisoners.
- For the first 40 days, while training, prisoners are paid £15 a week food allowance.
- After that, they are paid the minimum wage until released, but 40% of earnings go to a victims' fund.
- If prisoners are given a job on release, they would get the standard pay rate which is about £8 an hour, the service said.
The spokesman added: "It is crucial that prisoners have the opportunity to learn transferable employment skills to reduce the chances of reoffending, and therefore turning them away from crime."
Prescoed is a category D open prison near Usk for male inmates, with work placements part of vocational training, as well as the prison operating its own working farm.
A statement from the company - which provides solar panels and cavity wall insulation - said: "Becoming Green are proud that they along with other national and multinational corporations are taking on this responsibility to support the rehabilitation and resettlement of offenders.
"We work in partnership with HM Prison Services and comply fully to processes and procedures set out by government legislation."
The company added: "To reinforce the statement made by the Ministry of Justice we have just short of 200 staff of which only 23 are prisoners and once past training receive at least minimum wage - with a significant percentage of their income going to victim support.
"In addition no member of staff has lost their job to be replaced by a prisoner."