Unpaid internships have been likened to a form of modern slavery during a Lords debate on whether to ban them.
Lord Holmes asked how a country which "slammed the door on slavery in the 19th Century" could allow people to work for no financial return.
Interns were "not owned by anyone" and could quit, said Lord Mitchell, but getting "no payments for their labours" could be equated with slavery.
Baroness Brady said work experience had value but must be more skills-driven.
Lord Holmes' private members bill, being debated for the first time on Friday, would prohibit unpaid internships of more than four weeks. Without government backing, it is unlikely to succeed.
Ministers have previously opposed attempts to ban unpaid internships, arguing it could "undermine existing employment laws".
Three quarters of the 5,000 people surveyed said they backed a ban on unpaid internships lasting four weeks or more.
Many interns already fall under the legal definition of a "worker", a person who has a contract or arrangement to do work, and are entitled to the national minimum wage.
But Lord Holmes of Richmond said existing laws were clearly not working, given that more and more professions and trades were requiring unpaid work experience when it comes to securing a job.
"Wilberforce slammed the door on slavery in the 19th century," the Conservative peer, a former solicitor and member of the Equality and Human Rights Commission, said.
"We had the national minimum wage legislation in the 20th century.
"How can it still be in the fifth richest economy on the planet that in the 21st century we're still asking people to give up their labour for no financial return?"
The bill, he argued, would ensure young people had equal opportunities to get into the workplace.
'Not a job'
Businesswoman Baroness Brady said work experience had a role to play in informing young people about career choices and the world of work but was "very obviously not a job".
The Apprentice TV star, a former small business adviser to David Cameron, said employers had to think very differently about what its purpose was.
"They are not doing something an employer needs to have done for no cost.
"I think we need a change of mindset from those who might think of work experience programmes as something they can exploit to get something done for nothing, to a community-based approach."
Businesses, she said, should be asking what can we do to "give the young person the support they need to make that transition into the workplace and get on the road and to have a career?"
Ahead of Friday's debate, Tanya De Grunwald, founder of careers blog Graduate Fog, who campaigns for fairer wages for interns, said: "The bill is well-meaning but I think it's the wrong solution.
"The message should be that most unpaid internships are already illegal, with certain exceptions such as working for charities ... Our focus should be on enforcing existing minimum wage law."
She said she would like to see universities doing more to make young people aware of their rights and for it to be made easier to report advertisements for unpaid internships to HMRC.
In April, a report from the Institute for Public Policy Research found the number of internships had risen by 50% since 2010.
Research by the Sutton Trust, which works to improve social mobility, found nearly a third of graduate interns are unpaid. It estimated a six month unpaid internship in London would cost someone £5,556.