Shintaro Ishihara, coleader of Nippon Ishin no Kai (Japan Restoration Party) and Tokyo's former governor, has been hospitalized and isn't likely to be discharged until mid-March, sources said Saturday.

The 80-year-old Ishihara initially reported feeling ill from a severe cold after questioning Cabinet members at the Lower House Budget Committee on Feb. 12, according to the sources. He was admitted to a hospital in the middle of last week.

Ishihara made his return to national politics in December's general election, winning a Lower House seat on Nippon Ishin's ticket.