In a BBC documentary, Mr Cameron said that in 2014 he had asked if the Queen could intervene because he was concerned Scotland was going to vote for independence. The Queen later urged people to 'think very carefully' about the future.

Another former Conservative Prime Minister is also in the spotlight, as Sir John Major’s lawyers tell the Supreme Court that the current PM, Boris Johnson, was ‘dishonest’ about his reasons for suspending Parliament. Mr Johnson says progress is being made in Brexit talks with the EU.