Shingo Nishimura resigned Wednesday as parliamentary vice minister of the Defense Agency amid an outcry over remarks calling on Japan to consider arming itself with nuclear weapons.
Accepting his resignation, Prime Minister Keizo Obuchi later in the day informally appointed Taiichiro Nishikawa of the Liberal Party as Nishimura's successor.
It was the second blow to the tripartite ruling coalition in four days. On Sunday, the bloc's candidate lost a by-election in Nagano Prefecture in what was considered a litmus test.