Supreme Court judges are split over their historic Article 50 ruling, and look set to decide by a majority of seven to four to give Parliament a vote on when Britain leaves the European Union, Government sources believe.

The news that more judges than expected could back the Government’s argument is a boost for the Brexit side, as some had feared before the case that only one vote would be in the Government’s favour.

A narrow loss for the appeal will make it harder for Remain-supporting MPs and peers to frustrate the progress of a new law to trigger Article 50 of the Lisbon Treaty and start talks to leave the EU by the end of March.