Amnesty International on Tuesday approved a policy to endorse the decriminalization of the sex trade, a move that will lead to pressure on governments by the prominent rights group not to punish millions of sex workers worldwide.

At its decision-making forum in Dublin, the human rights group approved the resolution to recommend "full decriminalization of all aspects of consensual sex work." It argued its research suggests decriminalization is the single best way to defend sex workers' human rights.

“Sex workers are one of the most marginalized groups in the world who in most instances face constant risk of discrimination, violence and abuse,” said Salil Shetty, secretary general of Amnesty International. “Our global movement paved the way for adopting a policy for the protection of the human rights of sex workers which will help shape Amnesty International’s future work on this important issue.”

In a press release, the group said that the new policy has drawn on research from sources including the World Health Organization, UNAIDS, U.N. Women and the U.N. Special Rapporteur on the Right to Health.

In a Q and A released by Amnesty International, the group explained that it was calling for decriminalization rather than legalization, because legalization can lead to a “two tier system.”

"If sex work is legalized, it means that the state makes very specific laws and policies that formally regulate sex work," Amnesty said, adding that this means sex workers operating outside these regulations are still criminalized.

Decriminalization, the group argued, “places greater control into the hands of sex workers to operate independently, self-organize in informal cooperatives and control their own working environments in a way that legalization often does not.”

"I am thrilled," said Laura Lee, an Irish sex worker and activist. "It is the best way forward to take sex work out of the Dark Ages and give us the rights and protection we deserve."

The Women's Global Network for Reproductive Rights came out a few days ago in support of Amnesty's decision. The Global Network of Sex Workers Projects posted a petition supporting Amnesty on Change.org, and released a statement of their own. The Lancet, a British medical journal, recently published a series papers that found decriminalizing sex work would prevent between 33 and 46 percent of new HIV infections "across all settings" over next 10 years.

Advance word of the Amnesty policy touched off outrage among women's groups who argued that the human rights organization has made a serious mistake. The groups, such as the U.S.-based Coalition Against Trafficking in Women, have argued that while it agrees with Amnesty that those who are prostituted should not be criminalized, full decriminalization would make pimps "businesspeople" who could sell the vulnerable with impunity.

"It really is a slap in the face to survivors and to women's rights groups around the world," said Taina Bien-Aime, the executive director of the coalition.

Al Jazeera and wire services