SPD leader Gabriel expected to challenge Merkel in German election-sources

Germany's Social Democrats (SPD) are expected to choose their long-standing chairman Sigmar Gabriel to run against conservative Angela Merkel for chancellor in September's federal election, senior party sources said on Thursday. Gabriel, vice chancellor and economy minister in Merkel's right-left coalition for the last four years, is more popular with the SPD rank and file than his recent predecessors but also has a reputation for being impetuous and unpredictable. "There's no way around Sigmar