There's an extract in today's Guardian from a new book, The Blairs and their Court which contains the most extraordinary statement:
But Prince Charles was irritated by the informal style that Blair adopted in correspondence.
An American-style informality was a trademark of New Labour's modernising agenda; everybody in Downing Street addressed each other by first names and every letter from the prime minister was signed: "Yours, Tony". When Blair corresponded with the palace he signed himself in the same matey fashion, and he addressed the Prince of Wales not as "Your Royal Highness, the Prince of Wales" but as "Dear Prince Charles". The prince pointedly replied by writing "Dear Prime Minister" rather than "Dear Tony".
It's been standard business practice to call people you know by their first names everywhere in the West for at least the last 20 years. I find the idea that this is "American-style informality" quite bizarre - it shows quite how out of touch these people are. Perhaps the Windsors will eventually become so appalled by the presumption of commoners that they abdicate en-masse and let us have a republic by default.