Twenty-eight members of the House of Councilors are expected to retire from politics ahead of the Upper House poll slated for July 29, political sources said.
The members in question include Hisamitsu Sugano, vice president of the Upper House; Wataru Kubo, former deputy prime minister and finance minister; and former Labor Minister Yutaka Okano.
The number of Upper House members choosing not to seek re-election may increase as the poll draws closer, the sources said Tuesday.