A host of Hollywood stars, including Oscar-winning actresses Meryl Streep,
Kate Winslet and Emma Thompson, have lent their support to a petition demanding that Amnesty International reject a proposal to endorse the decriminalization of the sex trade.
The global human rights group is set to review an internal policy document on sex work at a meeting in Dublin next month, according to the Coalition Against Trafficking in Women (CATW).
If the policy is adopted, Amnesty would "in effect advocate the legalization of pimping, brothel owning and sex buying - the pillars of a $99 billion global sex industry", CATW said.
Nearly 2,600 members of the public have signed the petition since it was posted on change.org last week, and endorsed by women's rights campaigners and celebrities such as actors Emily Blunt, Lena Dunham and Anne Hathaway.
U.S.-based CATW said it agreed with Amnesty that sex workers should not be criminalized or brutalized by law enforcement agents and governments.
"However, full decriminalization of the sex trade renders pimps "businesspeople" who sell vulnerable individuals, overwhelmingly with histories of poverty, discrimination, homelessness and sexual abuse, to buyers of sex with impunity," the group said in a statement.
Amnesty International said it was in the final stages of receiving feedback on the draft policy, which is based on evidence that the criminalization of consensual adult sex work can lead to greater abuse against sex workers.
"These violations include physical and sexual violence, arbitrary arrest and detention, extortion and harassment, forced HIV testing and medical interventions and exclusions from health care, housing and other social and legal benefits," Amnesty said in a statement.
The rights group stressed that no decision had been made on whether to adopt the draft policy.
"Legalization keeps pimps, brothel keepers, and sex-slavers in freedom and riches. Criminalization puts the prostituted in prison," said veteran women's rights campaigner Gloria Steinem.
"What works is the 'third way', the Nordic model, which offers services and alternatives to prostituted people, and fines buyers and educates them to the realities of the global sex trade," she said in a statement.
The so-called Nordic model adopted by Canada, Sweden, Norway and Iceland, and more recently, Northern Ireland, aims to punish clients without criminalizing those who have been driven into
prostitution.
It contrasts with laws legalizing or decriminalizing prostitution, which have been introduced in the Netherlands, Germany and New Zealand.