Cameron digs heels in over plan to scrap benefits for eastern European workers

"Even if the Visegrad nations can be persuaded politically to accept this, anybody can go to the ECJ and say 'I'm being discriminated against'," said Charles Grant, director of the CER, a pro-European think-tank.

"British officials might argue that of discriminating 'for fiscal reasons' can be carried across to in-work benefits, but that’s not what a lot of lawyers think. If everyone signs up to it and the Commission signs up to it, it might just work, but it looks to be built on shifting legal sands."