US Edition A charity that helps women rescued from the sex trade said the Government was acting as a "pimp" by accepting advertisements for strippers, escort girls and lap dancers.
Denise Marshall, the director of the Poppy Project, told the Commons home affairs select committee that her organisation "had contact with" two 17-year-olds who gained access to explicit vacancies at a Jobcentre.
"Their mother and older sister contacted us because they were so distressed that this had happened," she said.
The computer system in the labour exchange did not ask applicants to confirm their age, she said. "Because no one is monitoring it, you don't know who is using it.
"And when you are offering £20 an hour to be a webcam stripper to a 17-year-old, the chances are they may be naive."
Outside the hearing, Miss Marshall said: "It's the Government as pimp. It's just dreadful. I'm appalled that the Government is giving women an entrée into the commercial sex industry."
Miss Marshall said she was not aware of any women becoming involved in prostitution from vacancies advertised in Jobcentres.
"It hasn't happened yet, but it will," she said.
The Department for Work and Pensions insisted that it was legally obliged to carry the vacancies after a test case brought by the Ann Summers sex shop chain in 2003.
A High Court judge ruled that Jobcentres must carry advertisements for legal work in the "sex and personal-services industries".
Damian Green, the shadow immigration minister, said: "This is a disgrace, especially when a huge percentage of prostitutes in Britain are victims of human trafficking from abroad."