NEWS ANALYSIS : Last Hurrah for Bulgaria’s Communists? : Politics: The only East Bloc country to return the ruling party to power gives it 18 months to change.

Bulgarian voters have given communism a new lease on life in Eastern Europe. But the rise of a vigorous opposition in this former totalitarian state will confront the first Communists to rule by popular demand with unrelenting pressure for progress that will be hard to come by.

The party that has governed for 45 years has never had to worry about the next election. Now, in an unfamiliar atmosphere of challenge, it has 18 months to build a democracy from the ruins of repression and heal economic ills acquired over decades.

Of the half-dozen nations freed from the Communist yoke last year, Bulgaria alone returned the ruling party to power after elections deemed free and fair by foreign observers.

Official results released Tuesday showed that the Bulgarian Socialist Party, as the Communists have renamed themselves, won at least 171 seats in the first round of voting Sunday, compared with 104 for the main opposition alliance. To have an outright majority, the party needs to win only one-third of the 84 seats that require recounts or runoffs.

Bulgarian Communists face the same charges raised against former rulers of other East European states--that they had ruined the economy, polluted the environment and systematically violated the rights of their own people.

In a nation where one in five adults belongs to the party, re-examination of its past crimes conjured up fears of reprisal in the event of an opposition win. For the nation’s nearly 2 million pensioners, stability was preferable to the promise of change and a better future they may not live to see.

The choice of the status quo points up Bulgarians’ resistance of the radical transition that is inflicting new hardships on old comrades in Poland and Hungary. It also highlights the vast differences among the nations of Eastern Europe that had little other than Communist domination in common.

Whether the new Socialists will succeed in easing the pain of transition for Bulgarians, who already lag behind the rest of the bloc in living standards, will depend on the opposition.

Young supporters of the 16-party Union of Democratic Forces took to the streets in a roving two-day demonstration after voting projections were broadcast Sunday night, denouncing the Socialists and calling for a general strike to protest the outcome they claim was a fraud.

Socialist Prime Minister Andrei Lukanov appealed to his countrymen “to look beyond party passions.” In a televised address, he repeated the winning party’s offer of a broad national coalition and said there were no losers in the vote that was a victory for democracy.

Zhelyu Zhelev, head of the opposition alliance, again rejected cooperation with the Socialists. “In the National Assembly, we will be a powerful opposition force,” he told supporters.

“This is the end of a one-party system--the opposition is a fact,” Petar Beron, the opposition campaign chairman, told cheering demonstrators.

Part of the opposition’s reluctance to share power with the Socialists is likely tied to fears of association with a government that may be doomed to fail.

Bulgaria faces the same colossal recovery problems as the other nations of Eastern Europe. Industry is concentrated in giant, inefficient production complexes that must be broken up into more manageable and privately owned enterprises. Production facilities thrown up hurriedly in the postwar buildup are badly in need of major repair or complete replacement.

Bulgaria also faces an $11-billion foreign debt at a time when production is tumbling and traditional markets for its goods are drying up.

The lack of an allied political party in Parliament, which the Socialists are likely to control by only a narrow margin, will make it difficult for the government to move quickly in drafting reforms.

The mountain of economic woes and the new opposition could combine to prevent the Socialists from showing results before the next election, and that would expose them to a disappointed electorate as well as a more experienced and organized opposition.

Bulgaria’s vote for communism will offer what could be a troubling basis for comparison with the emerging democracies that opted for a more radical pace of reform. Should Poland, Czechoslovakia and Hungary come to grips with rising prices and unemployment, the economic advances of their northern neighbors could fan anti-Communist sentiments in Bulgarians before the next ballot.

Conversely, if Bulgaria’s former allies are confronted with a painful and chaotic transition, the ruling party here stands to gain from a populace made to feel it chose the slower but surer model for reform.

Bulgarian economists are emulating much of Mikhail S. Gorbachev’s perestroika policy, which they contend can work in a small nation of 9 million better than in the vast Soviet Union torn by political and ethnic strife.

But even the most optimistic predict a worsening of Bulgarian living conditions before stability or improvement can be achieved.

“There is going to be unemployment and inflation. There is no way we can avoid this,” said Rumen Gechev, a professor at Sofia’s Institute of Economics. “There are going to be some very hard times.”