Sex worker and law graduate Laura Lee is steeling herself for a battle in Belfast’s high court that she believes could make European legal history. The Dublin-born escort is now in the final stages of a legal challenge to overturn a law in Northern Ireland that makes it illegal to purchase sex.

Not a single person in the region has appeared in court charged with trying to hire an escort, though Public Prosecution Service figures show that three are under investigation. The region is the first in the UK to make buying sex a crime. The law was introduced in 2014 by Democratic Unionist peer Lord Morrow and supported by a majority of members in the regional assembly.

But Lee will enter Belfast high court with her team of lawyers aiming to establish that the criminalisation of her clients violates her right to work under European human rights law. Since the law was established, Lee insists that the ban has put her and her fellow sex workers in more peril from potentially dangerous clients.

Just before flying out to address an international conference on sex workers’ rights in Barcelona this weekend, Lee told the Observer that most men currently seeking escorts in Northern Ireland no longer use mobile phones to contact her and her colleagues.

“They are using hotel phones, for example, to contact sex workers in Belfast rather than leaving their personal mobiles. This means if one of them turns violent there is no longer any real traceability to help the police track such clients down. Men are doing this because they fear entrapment and arrest due to this law.

“So in a sense the law is actually putting sex workers at greater risk than before, when there was some ability to trace and track down any client that was violent and abusive. The law to protect women in the sex trade has done the opposite of what it was intended to do. Every escort I know working in Belfast now insists on working side by side with another woman for protection. The law has not in any way reduced demand and supply, which is still the same. It has only driven the business further underground.”

Laura Lee with supporters at the Belfast high court. Photograph: Charles McQuillan/Getty Images

Among those supporting Lee is Amnesty International. Before the court hearing, Amnesty’s campaign manager in Northern Ireland, Grainne Teggart, said they had major concerns about the “Morrow law”: “Sex workers are at heightened risk of a whole host of human rights abuses including rape, violence, extortion and discrimination,” said Teggart.

“Far too often they receive no, or very little, protection from the law or means for redress. Laws must focus on making sex workers’ lives safer and improving the relationship they have with the police, not place this relationship at risk by criminalising them and the context in which they work. Similar laws in Nordic countries have failed to decriminalise sex workers, who are still pursued and punished under remaining sex work laws.”

Lee’s Belfast legal battle is only the start of a Europe-wide campaign to overturn the model in which Scandinavian countries pioneered the outlawing of men buying sex. Lee’s next target is the Irish Republic, which, under new anti-trafficking laws, has introduced a similar ban aimed at criminalising clients.

“A win for us in Belfast will have a knock-on effect and set a precedent across Europe. If successful up north there will be a challenge in Dublin and sex workers across Europe can use the precedent to overturn the so-called ‘Nordic model’ in their countries,” she said.

From the outset, Lee said she had expected a “tsunami of abuse” on social media from her opponents, an alliance of religious groups and some feminist organisations on the island of Ireland. “In the hate mails they focus a lot on my daughter and say things like ‘I really can’t wait until your daughter goes on the game’ and vile things like that. Religious people tell me they can’t wait until I burn in the fires of hell – charming really! But they must know I am dogged in my determination to fight this law on behalf of all sex workers, especially the ones that can’t put their heads above the parapet and take a public stand. I am strong enough to do so and can take their abuse.”

Not even Brexit will stop Lee from taking her challenge all the way to Europe: “The European court of human rights does not just apply to EU countries, so it matters not that the UK, including Northern Ireland, is leaving the union. Citizens’ rights are still covered outside of the EU by the European court and if necessary that is where I will go to get this unjust, counterproductive law overturned,” she said.