Japanese Prime Minister Shinzo Abe resigned on Wednesday after voters deserted his scandal-plagued government and an emboldened opposition refused to back his ambitious reform agenda.
After just one year in office, a visibly emotional Abe said that a resurgent opposition was making it impossible for him to continue in the job.
"I have made my utmost efforts with my belief that we should not stop reforms. But unfortunately, the party cannot hold talks with the opposition party because I am the prime minister," Abe told a press conference.
"I thought the party should generate new momentum and progress under a new leader," he added.
Abe said he had instructed his Liberal Democratic Party to pick a successor "as soon as possible."
He said he decided not to delay his decision to step down any longer to avoid causing confusion in parliament.
Abe, Japan's first premier born after World War II, and at 52 the youngest in modern times, took office last year with pledges to end legacies of defeat, including by rewriting the US-imposed pacifist constitution.
But his approval ratings nosedived amid public perception he lacked authority following a raft of scandals, including massive mismanagement of the pension system -- a sensitive issue in a rapidly ageing country.
The opposition has being doing its utmost to block Abe's reforms as well as legislation to extend a controversial military mission providing refuelling support to US-led operations in Afghanistan.
Abe has staked his job on the need to extend the mandate for the mission, which polls show is unpopular with voters.
But opposition leader Ichiro Ozawa of the Democratic Party of Japan (DPJ) has vowed to use his bloc's new-found power in parliament to fight against Tokyo's logistical backing for US forces.
The opposition has also been expected to seek symbolic censure motions against the scandal-hit cabinet ministers and possibly Abe himself.
Abe brought in party veterans to take up key positions in his cabinet after a major upper-house election defeat in July.
But just one week later his new farm minister resigned over financial wrongdoing.
Taro Aso, the LDP secretary general and a former foreign minister known for his blunt, conservative views, is seen as one of the front-runners to replace Abe.