The 59-year-old Mr Hata, who exactly a year ago led a revolt against the LDP to break the mould of Japan's corrupt, inward-looking politics, yesterday fell victim to the skeletons of that old system. The LDP, derided until recently as a dinosaur of the Cold War, may now form Japan's next government.
Mr Hata's aides negotiated into the early hours of yesterday in an attempt to persuade the Socialist Party to rejoin his coalition, and stave off the no- confidence vote that could have led to the dissolution of the Diet and new elections.
But the Socialists, whose left-wing views have increasingly marginalised them in Japan's body politic, seemed to relish their new role as the swing voters, and pressed for unreasonable concessions.
'If the Lower House is dissolved, there will arise a political vacuum, and it becomes impossible to tide over the yen's appreciation and other problems,' Mr Hata said after announcing his resignation.
It would be particularly embarrassing for the Japanese government to be fighting an election campaign during next month's Group of Seven summit in Naples, reviving the paralysis during last year's G7 summit, when Japan was also preparing for elections.
The Diet will reconvene on Monday to elect a new prime minister. Yesterday feverish negotiations were going on to decide who will form the next government. The most likely - if most cynical - alliance would be between the LDP and the Socialists. They were bitter enemies for the 38 years that the LDP ruled Japan during the Cold War. But they share an interest in derailing the electoral and political funding reforms Mr Hata's government was trying to push through.
Another possibility is for Mr Hata to renegotiate a deal with the Socialists, who left his coalition two months ago. But whatever the outcome of the deal-making, Mr Hata's longer- term goals of reforming Japan's political system and making the country more responsive in the international arena now seem to be on hold.