MIDDLE EAST NEWSMARCH 31, 2011 In Key Defection, Libyan Minister Resigns His Post By DAVID GAUTHIER-VILLARS, ALISTAIR MACDONALD and MARGARET COKER In a major diplomatic setback to Col. Moammar Gadhafi, Libya’s foreign minister Moussa Koussa resigned from his position and may announce his defection as early as Thursday, European government officials said. A British Foreign and Commonwealth office spokesman said. Mr. Koussa arrived in England from Tunisia Wednesday where he resigned his position as Libyan Foreign Minister, Reuters Libyan Foreign Minister Moussa Koussa in 2010. “He travelled here under his own free will,” the spokesman said. The U.K. is currently in discussions with Mr. Koussa, the spokesman said, declining to…