Spain's Sánchez digs in after eight years as PM as wave of scandals threatens survival NurPhoto via Getty Images Pedro Sánchez has not been directly implicated in any of the investigations, but allies and relatives have 1 June marks exactly eight years since Pedro Sánchez became prime minister of Spain, but with his government and Socialist Party besieged by corruption investigations he is more likely to be plotting his political survival than celebrating. His musician brother, David, has just gone on trial accused of influence peddling. Former Socialist prime minister and close Sánchez ally José Luis Rodriguez Zapatero has been named in an investigation into alleged money laundering. And police have raided the Socialist headquarters in Madrid as part of a probe into allegations of a dirty tricks campaign that the opposition has dubbed "the Socialists' Watergate".…