Sir Vince Cable has one of the most recognisable faces in British politics. Right now it looks a little tired, which is telling for the Liberal Democrat leader — he needs all the energy he can muster if he is to deliver on his promise of stopping Brexit.

The 74-year-old, who was crowned leader of the Lib Dems last July, has set his party up to be the political alternative to a hard exit from the European Union, or what he called an "exit from Brexit" in his maiden speech as party leader.