The Monday defection of Kunio Hatoyama from the Liberal Democratic Party has caused a stir in the former ruling party that for most of the postwar era was an electoral juggernaut. But experts and lawmakers say it is unlikely to create a fundamental power shift.

The ruling Democratic Party of Japan, for its part, seems less than impressed. The younger brother of Prime Minister Yukio Hatoyama "is touting a change of government, but he probably means a realignment of the LDP," DPJ Diet Affairs Committee Chairman Kenji Yamaoka told reporters Tuesday.

The veteran lawmaker insisted the DPJ is unaffected by the younger Hatoyama's decision, and maintained the ruling bloc is untroubled by strife in the opposition.