Amnesty International, which has long counted on the support of celebrity heavyweights like Anne Hathaway, U2 and Jon Stewart, now finds itself on opposite ends with liberal Hollywood -- over legalizing prostitution.

The human rights group next month in Dublin, Ireland, will consider a new policy that calls for the global decriminalization of sex trafficking. That proposal has drawn the ire of celebs like Meryl Streep, Kate Winslet – and Anne Hathaway – who've joined over 400 others in signing a letter from the Coalition Against Trafficking in Women (CATW) that protests "a policy that calls for the decriminalization of pimps, brothel owners and buyers of sex — the pillars of a $99 billion global sex industry."

Taina Bien-Aimé, executive director of CATW, told FOX411 that Amnesty's move to legalize prostitution would leave an already vulnerable population in even direr straits.

“A prominent human rights organization like Amnesty should be listening to the sex trade victims, women’s rights groups and imploring them to not decriminalize the pimps, the brothel owners, and the sex buyers," Bien-Aimé said.

Amnesty International has heard the CATW and its celeb supporters loud and clear, but says it has not made up its mind on its stance on the issue.

“Amnesty International has not made a decision yet on this issue. It is important to stress that given that the consultation process is still on-going, no decisions have been made,” Amnesty’s Deputy Executive Director Cammie Croft told FOX411. “No policy has been adopted by Amnesty International and it is not possible to speculate about the eventual outcome of the vote.”

But Croft says something needs to be done. 

“Sex workers are one of the most marginalized groups in the world so it is important that we understand how, as Amnesty International, we can work to support their human rights. The violations that sex workers can be exposed to include physical and sexual violence, arbitrary arrest and detention, extortion and harassment, human trafficking, forced HIV testing and medical interventions,” Croft said. “They can also be excluded from health care and housing services and other social and legal protection.”

The sex-trade policy Amnesty is considering is similar to the German model that was adopted in 2002. According to Bien-Anime that model has resulted in “explosive growth of legal brothels in Germany that has triggered an increase in sex trafficking.”

CATW supports the Nordic Model, the world's first law to recognize prostitution as violence against women and a violation of human rights. Bien-Aime says this model “criminalizes the purchase of commercial sex and offers women and children an exit strategy.”

So far, The Nordic Model, which originated in 1999 in Sweden, has been passed in the Republic of Korea, Norway, and Iceland, Canada, and most recently Northern Ireland.

But civil rights attorney Ameer Benno contends that legalizing prostitution will protect sex workers and allow them the same benefits and protections as other legitimized employees.

“Sexual commerce should be treated like other kinds of work, and sex workers like workers in other occupations," Benno said. "That means that they should be afforded the full panoply of rights, protections, and responsibilities that come along with that, without stigma. Look, abuse, exploitation, and violence are unquestionably bad things that we all should aspire to eradicate, but they are by no means inherent in prostitution."

FOX411 reached out several celebs who signed the CATW letter, including Meryl Streep, Lena Dunham, and Lisa Kudrow, but did not receive comment. Bien-Aimé, though, says she is happy to have their support. “These women just happen to be celebrities but they are women first. They care about women’s rights and they care about a future where violence against women doesn’t exist. We’re grateful that leaders like Meryl Streep and Anne Hathaway are standing with women that are exploited rather than pimps and Johns."

Amnesty International has not shied away from support from the Hollywood community, but doesn’t prioritize it, Croft said.

“As the largest grassroots human rights organization in the world, defending and protecting the rights of the most vulnerable is our greatest concern,” Croft said.

Fox News.com Reporter and FOX411 host Diana Falzone covers celebrity news and interviews some of today's top celebrities and newsmakers.  You can follow her on Twitter @dianafalzone.