Is the right hon. Gentleman aware that there are many thousands of these houses in existence, to the knowledge of hon. Members on both sides of the House, and that some of the worst are in the Prime Minister's constituency? In Kinross there are houses with holes in the walls and holes in the floors. They are being held up by wallpaper almost, but the Prime Minister does nothing about them. Can the right hon. Gentleman give an undertaking that these houses will be cleared within ten years?