David Cameron promised to get the rules changed in order to stop migrant workers who come to Britain from other EU countries claiming child benefit and sending it home

Migrant workers can claim child benefit even if their children live in a different country, the European Union’s top court ruled yesterday.

In a possible set-back to David Cameron’s renegotiation of the UK’s EU membership, the European Court of Justice confirmed that parents living in one member state are entitled to claim the welfare payments and send them to their children living in another.

The judgment, in the case of a man in Germany whose child was living with his ex-wife in Poland, comes as the Prime Minister prepares to set out his demands for EU reform.

Mr Cameron has promised to get the rules changed in order to stop migrant workers who come to Britain from other EU countries claiming child benefit and sending it home.

Making his pledge in November last year, he said: ‘People cannot understand how those who have not paid in can immediately take out, and they find it incomprehensible that a family coming from another EU country can claim child benefit from the UK at UK rates and send it back to children still living in their home country. When trust in the European Union is already so low, we cannot leave injustices like this to fester.’ He added: ‘If your children and your family is at home in your home country while you’re working here, the child benefit will not go from Britain to that country.’

Eurosceptics last night claimed that the ruling from the Luxembourg-based ECJ revealed the opposition in the EU to Mr Cameron’s proposal. However, the ruling could help to convince Germany – the most powerful country in the EU – of the need to change the rules.

Robert Oxley, spokesman for the Vote Leave campaign, said last night: ‘Under EU law the UK has lost control of who it can hand benefits to.

‘Un-elected EU judges have ensured the UK cannot stop child benefit payments from being exported to the continent, despite promises by the PM to end the practice.

‘It’s becoming clearer every day that the renegotiation is a smokescreen. The only way to take back control is to Vote Leave.’ Yesterday’s case was referred to the ECJ by the German courts after worker Tomislaw Trapkowski tried to claim child benefit in August 2012 for his son, who was then aged 12 and lived in Poland with his mother, but was told he was not entitled to them.

The European Court of Justice (pictured, the building in Luxembourg) confirmed that parents living in one member state are entitled to claim the welfare payments and send them to their children living in another

But the ECJ said yesterday: ‘A person may claim family benefits for members of his family who reside in a member state other than that responsible for paying those benefits, as if they resided in that member state.’

The ruling came a day after one of the Government’s most senior officials in the renegotiations warned that Mr Cameron will fail to get his key EU demand to stop benefits being handed out to working migrants who have been in the country for less than four years.

The diplomat said he expected there would only be an agreement to restrict welfare payments for a matter of months because of fierce resistance from other EU countries.