Evelyn Waugh Vile Bodies (1930)
"It is one very extraordinary thing, your British Constitution," said the ex-King of Ruritania. "All the time when I was young they taught me nothing but British Constitution. My tutor had been a master at your Eton school. And now when I come to England always there is a different Prime Minister and no one knows which is which."
"Oh, sir," said the Major, "that's because of the Liberal Party."