(ANSA) - BELGRADE, JUL 18 - Jens Spahn, the Union Party's (CDU/CSU) leader in Germany, has resigned in the wake of the controversy surrounding his father's birth in the United States via surrogacy. This is according to Spahn's letter to members of the CDU/CSU parliamentary group, which was obtained by the German news agency dpa. Chancellor Friedrich Merz had requested his resignation. (ANSA).