After winning EU deal, Britain's Cameron faces harder battle

By Elizabeth Piper LONDON (Reuters) - When Prime Minister David Cameron sealed a deal designed to keep Britain in the European Union after two days of talks in Brussels, his relief was short-lived. Within hours of Friday's agreement, one of Cameron's closest allies, Justice Secretary Michael Gove, and five other ministers declared they would campaign against him in a June 23 referendum on whether Britain should stay in the bloc. It was the first blow in what could be a new "civil war" in Cameron