I have no strong opinion about David Cameron but I don't think h e has said anything wrong in describing Britain as a christian country. Our main holidays are Christmas and easter, the head of state needs to be protestant and much of our history and traditions are based around the christian religious calendar. We are moving to a more secular society but I can't see these traditions dying out. I live in a very multi cultural area where all festivals are celebrated. I have friends from many cultures who are not alienated by the christian festivals. Many send Christmas cards as a mark of respect (and some just celebrate Christmas because they like the festival) some people are not religious but will celebrate these festivals in some form ie buy an Easter egg for their children, celebrate pancake day.