Live coverage of HM The King's visit to Scotland, where he will attend a special service for HM The Queen and visit the Scottish Parliament.

Once a week, the prime minister had a private audience of the Queen, just as Sir Winston Churchill did at the start of her reign. With the help of her surviving prime ministers, William Shawcross examines this critical relationship at the heart of our constitutional system. Featuring interviews with Baroness Thatcher, Lord Callaghan, Sir Edward Heath, Sir John Major and Tony Blair.