The hardline approach, enshrining the authority of the European Court of Justice on Britain, was backed yesterday by the new president of the European parliament

Brussels is demanding lifelong rights for EU citizens and their families in a move that would overturn Theresa May’s pledge to end the power of the European Court of Justice (ECJ) in Britain.

Leaked European Commission negotiating guidelines reveal that the EU is demanding that Mrs May indefinitely submit to rulings by the ECJ on the pensions, employment and welfare rights of the three million EU citizens living in the UK.

It will raise concerns that Britain will be held to account by the Luxembourg court over benefits for EU citizens and their right to bring relatives, including non-Europeans, to live with them. If a deal were struck, the 900,000 British citizens living in Europe would have the same rights.

A separate European Council document