Congress president Sonia Gandhi was stopped by her son, Rahul, from becoming prime minister in 2004 because he was scared she too would fall victim to political assassinations that had earlier ravaged the Nehru-Gandhi family, former foreign minister K Natwar Singh revealed on Wednesday.br br After winning a surprise election victory in 2004, Sonia faced stiff opposition from several senior party leaders, including Sharad Pawar and PA Sangma who cited her Italian antecedents to stop her becoming prime minister.