** FILE ** U.S. President George W. Bush, right, talks with British Prime Minister Tony Blair, left, during the opening session of the NATO summit in Istanbul, Turkey, in this Monday, June 28, 2004 file photo. Blair signaled his resignation as leader of the Labour Party Thursday May 10, 2007, opening the way for a leadership contest which is expected to be won by present Chancellor of the Exchequer Gordon Brown.(AP Photo/Charles Dharapak)