Former Prime Minister Junichiro Koizumi, one of the most popular and influential politicians in the nation, expressed his intention Thursday to retire from politics once his current term in the Lower House ends.

Koizumi's retirement will have a profound impact on domestic politics. Many lawmakers had expected him to play an important role in realigning political parties after the Lower House election widely expected later this year.

In video footage aired by NHK, a grave-faced Koizumi, 66, nodded silently when reporters in his hometown of Yokosuka, Kanagawa Prefecture, asked Thursday evening if he was going to retire from politics.