Europe’s top court has been told that British Prime Minister David Cameron’s legal case for blocking the welfare benefits of European Union (EU) migrants has been ‘lost in translation’.

At the European Court of Justice (ECJ) in Luxembourg, Britain finds itself locked in a battle with the European Union Commission over plans to restrict the ability of migrants from claiming welfare benefits during their first 4 years of residency in the UK.

A major part of the dispute rests on an apparent mistranslation of German and French transcripts of previous court rulings, which confirm that governments are not obliged to pay emergency social assistance payments to unemployed migrants.

However, during the hearing, council for the EU Michael Wildersian accused the UK government of trying to extend the scope of the rulings to incorporate non-emergency social security payments.

“What the UK regards as references to social security are simply mistranslations of what was said in the French and German texts, prestation sociales and sozialleistungen [social assistance] not social security benefits,” said Wildersian as reported by The Times.

“The UK is trying to extend the clear wording beyond social assistance to pure social security.”

The ECJ always uses the French language as well as the language of the country involved in the legal dispute for drawing up legal texts. In this courtroom battle, the cases in question are a German and Austrian case respectively, meaning that the pertinent documents are written in French and German.

“The British case rests on a translation error,” a legal source at the EU has said.

The differentiation in European legislation between granting resident EU citizens a right to social security (such as family benefits) and preventing new, unemployed EU migrants from claiming emergency funds is clear. Thusly, the ECJ’s advocate general upheld the ruling that emergency funds could be denied to recent jobless migrants. This means that David Cameron has the ability to restrict migrant payments for the first three months of their UK residency.

However, the advocate general said that the ruling does not extend to the PM’s plans to prevent migrants from receiving benefits for their first 4 years of residency in the UK.

Acting on behalf of the government, Jason Coppel QC waded in to argue that the rulings did in fact apply to all social security payments:

“The commission says the principles laid down [in case law] apply only to special non-contributory benefits, or SNCBs, which form part of the social assistance system of a member state. The principle applies, I quote, to “social security benefits” and not just SNCBs.”

A spokesman for the Open Europe think-tank said that the hair-splitting over the issue proves that the PM is right to argue for an overhaul of the rights of movement system.

“Current EU rules on access to national welfare systems are inconsistent and contradictory, and the UK is right to push for reform to ensure migrants must contribute before they can claim,” he said.