The home secretary and lord chancellor were tight-lipped this week on details of the government’s plan to opt out of more than 130 EU crime and justice measures. In evidence to a Lords committee, Theresa May said the government had indicated its ‘direction of travel’, signalling its intention to exercise the block opt-out agreed by Labour when negotiating the Lisbon Treaty.

But neither she nor Chris Grayling was able to give details of which measures the UK would seek to opt back into, or how it would plug the gap left by the withdrawal of facilities such as the European arrest warrant.