TOKYO — Bolstered by an upswing in the voter turnout, Japanese Prime Minister Yasuhiro Nakasone's ruling party regained a majority with a victory of landslide proportions in the powerful lower house of Parliament, results from Sunday's election for both houses of Parliament showed today.
With four contests left to be decided, the ruling Liberal Democratic Party was assured of 304 seats, far in excess of the 271 it needed to control all standing committees in the lower house. Along with 300 of its own winners, four conservatives who won without party affiliation also were expected to join the party.
That outcome represented a gain of at least 46 seats, compared with the last election in December, 1983, when the Liberal Democrats, under Nakasone's leadership, suffered their worst-ever setback in the lower house.
In no earlier election had the ruling party shown a net gain of more than 31 seats, and not since 1969 has it held more than 300 seats in the lower house.
The sweeping victory, which exceeded even the most optimistic forecasts for the ruling party, was considered certain to spur calls for a revision of party rules, which now dictate that Nakasone must step down Oct. 30.
A victory giving the Liberal Democrats more than 271 seats had been regarded as the minimum needed to encourage moves to retain Nakasone.
Reacting to expectations of the ruling party's victory, the yen's value rose to an all-time high of 158.90 to the dollar shortly after the Tokyo Foreign Exchange Market opened this morning at 159.70 yen to the dollar. The previous record, set May 12, was 159.99 to the dollar for a single transaction.
At 11:30 a.m., the yen was trading at 159.05, a 52.2% appreciation since finance ministers of Japan, the United States, England, France and West Germany agreed last Sept. 22 to drive down the value of the dollar.
Opposition parties had attacked Nakasone for his failure to halt the rapid appreciation of the yen, and the Bank of Japan, which traders suspected was trying to hold down the yen's value on the eve of the election, was reported to have purchased more than $2 billion worth of the American currency last week.
Prices on the Tokyo Stock Exchange also jumped 169.59 points to a new record of 17,764 yen by noon.
The Liberal Democrats scored gains throughout the country, including the Tokyo region and other urban areas where opposition parties had counted most of their strength. The big losers were the Socialists, the No. 1 opposition party, which appeared headed for its worst-ever results.
With four seats remaining to be decided, 300 Liberal Democrats had been declared elected. The addition of the four conservatives to the Liberal Democratic victors was expected to give Nakasone at least 304 seats, a majority of 48 in the 512-seat chamber.
The biggest single-election gain scored by the ruling party, including unaffiliated winners who joined the party after the election, came in 1980, when they won 289 seats for a majority of 34.
Socialists had obtained 83 seats, while the neo-Buddhist Komei (Clean Government) Party had won 55, the middle-of-the road Democratic Socialist Party 26 and the Communists 25. Fifteen others also won.
The voter turnout of 71.4% exceeded the 67.94% of three years ago, when the Liberal Democrats lost 31 seats and their majority was slashed to a razor-thin margin of two, including unaffiliated winners who joined the party immediately after ballots were counted.
Because of deaths since 1983, the Liberal Democrats held only 250 seats going into Sunday's election. They had retained control of the lower house only with the help of a "mini-coalition" with the New Liberal Club, a conservative splinter group that held eight seats before Nakasone dissolved the lower house June 2.
The turnout fell short of the 74.57% turnout in 1980, the only other time Japan ever held a "double election" for both houses of Parliament simultaneously. In that election, the Liberal Democrats scored their biggest previous win.
Cloudy skies with an absence of heavy rain, which had prevailed through much of the rainy-season campaign, provided what Nakasone on Sunday called "rather good weather" for voting: gloomy enough to discourage family outings but good enough to encourage voters to go to neighborhood polls.
Incomplete returns from the upper house election assured the Liberal Democrats of retaining a comfortable majority in the 252-seat chamber.
The ruling party got a boost partly because 61 of its 1983 candidates finished as runners-up in multi-seat constituencies in the last lower house--far more than for all the opposition parties. Large numbers of those 1983 losers, who had been campaigning consistently for 2 1/2 years, regained seats this time.