More than 200 women's rights groups are calling for laws to make paying for sex a crime across the European Union.
Campaigners presented key policy recommendations for legislation to MEPs in Brussels on Wednesday.
"Prostitution is a form of violence, an obstacle to gender equality and an open door for organised crime to develop," a campaign spokeswoman told the BBC.
But opponents say the move is likely to drive the prostitution industry further underground.
The European Women's Lobby (EWL), which leads the campaign, wants EU member states to implement six key policies, including the criminalisation of all forms of procuring, and the creation of effective exit programmes for sex workers.
"The most important thing to understand about prostitution is that imposing sexual intercourse with money is a form of violence that shouldn't be accepted," EWL spokeswoman Pierrette Pape told the BBC.
"If we understand that, we can then put comprehensive policies into place that will change mentalities and respect gender equality between women and men."
EWL cites Sweden as a successful example, saying that street prostitution had halved there since paying for sex was outlawed a decade ago.
In contrast, there has been no significant improvement of the conditions of sex workers in the Netherlands where the sector has been legalised, Ms Pape said.
She said the issue now needed regulating on an international level, beyond country-specific laws.
"It is a problem that knows no political and geographical boundaries," she said, adding that EU policies on human trafficking would not be effective unless they also addressed prostitution.
"There is a legal base in the treaties to address the transnational crime of the sexual exploitation of women and children."
So far 36 European MEPs are already supporting the proposal, Ms Pape said.
Critics, however, argue that criminalising prostitution also increases the risk of rape and violence.
The UK Network of Sex Work Projects (UNSWP) believes the move would have damaging consequences for prostitutes.
"It creates a legal and policy climate, in which sex workers are more stigmatised and socially excluded, and in which it is harder to offer [them] accessible support services," the organisation told the BBC.
"It erodes sex worker safety and rights. The council of Europe should reject such laws and [instead] support initiatives and legal changes, which improve the social status and safety of sex workers and allow criminal justice authorities to focus their limited resources on violent and other crimes committed against sex workers."
Many sex workers say the sector needs more transparency and better regulation, the BBC's Maddy Savage reports from Brussels.
In the Netherlands, Austria and Germany, prostitutes register their services in return for the same rights and responsibilities as people running other kinds of businesses.
The EU currently does not have the power to legislate on prostitution. But new laws designed to reduce human trafficking are set to come into force next year and EU officials told the BBC both issues are closely linked.
They are currently analysing different countries' approaches and are expected to report back on their findings in 2016.