An unemployed graduate is challenging the legality of a government work experience scheme that she says forced her to work for free in Poundland.
Cait Reilly, 22, said she had to leave her voluntary work at a museum to stack shelves in the budget store for two weeks or risk losing her unemployment benefits.
Her legal team is asking a judge at London's High Court on Tuesday to quash Department for Work and Pensions regulations under which the "sector-based work academy" workfare scheme was set up to help young unemployed people into work.
They say the requirement under the 2011 regulations to carry out mandatory work breaches article 4 of the European Convention on Human Rights, which prohibits slavery and forced labour.
Reilly, a geology graduate from Birmingham University, said she was sent under her scheme to an employment skills training workshop for a week to improve attributes such as communication skills.
That was followed by five hours a day sweeping up and stacking and cleaning shelves at the Poundland near her home in Kings Heath, Birmingham, before having to attend a final week of training on the scheme.
A promised job interview never materialised.
In a second case, judicial review is being sought by a claimant who refused to take part in another scheme under the regulations called the "community action programme".
Public Interest Lawyers (PIL), who are acting for both claimants, say he was told that he had to work cleaning furniture without pay for 30 hours a week for six months.
"No detailed information or guidance was provided to him about the scheme itself, and he has recently been informed that he is being stripped of his jobseeker's allowance for six months because he refused to participate in the scheme," said PIL.
In both cases the lawyers argue that the regulations wrongly left the design of the schemes to be decided by the secretary of state from time to time.
They contend that that was unlawful and the 1995 Jobseekers' Allowance Act required each scheme to be set out in the regulations.
PIL accuses the government of using vague and open-ended regulations to create a plethora of schemes without publishing clear guidance as to what they entail.
The lawyers say the result is "complete confusion", as evidenced by the Queen's Jubilee "work programme" - another scheme made under the 2011 regulations - when there were accusations of those on the programme being required to work 14-hour shifts as security guards after sleeping rough under London Bridge.
Jim Duffy, Reilly's solicitor, said: "Everyone agrees on the need to help the unemployed back into work, but forcing young people into pointless, unpaid labour at massive retailers who could easily afford to pay them the minimum wage demeans and frustrates them when we should be empowering and supporting them.
"These Orwellian schemes are about work for its own sake rather than for any greater purpose."
Joanna Long, a member of the Boycott Workfare campaign group, said: "If these cases succeed, the Government would see their workfare schemes in even deeper disarray.
"We wish the claimants our best wishes with their cases, in which they will assert their right, and the rights of all unemployed people, to be protected from forced work for benefits."
A DWP spokesperson said: "We will be contesting these cases vigorously. These schemes are not slave labour. They play an important part in giving jobseekers the skills and experience they need to find work.
"It is entirely reasonable to ask jobseekers to take real steps towards finding work if they are claiming benefits."