Prince William hit headlines earlier this month when pictures of him on a wild boar hunt in Spain emerged as he prepared to launch a new charity drive with his father Prince Charles to ban the killing of elephants and rhinos.On Monday, William's brother Harry became a target when a picture was published online showing him posing with a gun next to the body of a dead water buffalo in Argentina in 2004.Now passionate animal rights advocate May has waded into the debate, branding the Princes' passion for hunting sickening.He tells The Sun newspaper: "It made me feel sick. This is right at the heart of the problem we are looking at in this government. "It's the whole attitude of the privileged classes - you can rescue rhinos and elephants in Africa but kill at will anything you want if you're rich. It's an attitude I'm very familiar with as I'm used to talking to people who justify tearing living foxes apart with packs of dogs."It's not logical, justifiable or humane and is the same as people in the 19th century trying to justify slavery. That is an archaic way of thinking and it has to go."Another veteran rocker, Morrissey, has also criticised William's hunting, labelling the Prince a "thickwit" and branding the royal family an "embarrassment" to the UK.