Gruenwald was sued for libel by the Israeli government on Kasztner's behalf, resulting in a trial that lasted two years. Gruenwald's attorney, Shmuel Tamir, was a former Irgun member and supporter of the opposition Herut Party led by Menachem Begin. Tamir turned the libel case against his client into a political trial of Kasztner and, by implication, the Labor Party. The mother of wartime heroine Hannah Szenes had also accused Kasztner of betraying her daughter to her death and spoke out against him during the trial.