By Sachin Ravikumar LONDON (Reuters) – British rock singer Rod Stewart made a surprise phone call to a live TV news programme on Thursday to slam the “ridiculous” state of the health system, urge the government to stand down and give the opposition Labour Party a chance. Stewart, known for his 1970s hits “Maggie May” and “Do Ya Think I’m Sexy?,” called in to a Sky News programme about the crisis in Britain’s National Health Service (NHS) that had been taking calls from members of the public. “This is heartbreaking for the nurses,” Stewart said. “It really is heartbreaking. In all my years of l…