MOSCOW, JUNE 18 -- The Soviet Communist Party's leading conservative, Yegor Ligachev, called today for a referendum on whether the country should follow a socialist or capitalist path.

In an interview with the party newspaper Pravda, Ligachev questioned the wisdom of Soviet leader Mikhail Gorbachev's drive to convert command-administrative economic system to a more market oriented model. Ligachev, a member of the party's ruling Politburo, said he is firmly against the establishment of private property and is concerned that the country might be headed for a restoration of capitalism.

"Those who advocate a free market are pushing us back to the private appropriation of the fruits of the labor of other people and exploitation of those people," Ligachev said.

Ligachev defended the current economic system against capitalism. "The principle of freedom to the detriment of others is dangerous," he said. "It has already brought mankind to the brink of a catastrophe in the past, which, if we look at it without bias, was prevented by socialism, no matter how deformed."

With a crucial congress of the Russian republic's Communist Party set to begin Tuesday and the 28th National Party Congress scheduled to start July 2, Ligachev has been setting out the conservative agenda in the press, expressing anxiety about the "loss" of Eastern Europe and the restoration of "dangerous" economic concepts, such as free markets. He has also called for a purge of party ranks.

Earlier this month, at a conference of peasants in Moscow, Ligachev accused Gorbachev and others in the leadership of making "concession after concession," and went on to say that "if compromises are made endlessly, everything could be lost." He said that if Gorbachev continued to decentralize power, he would soon be a "president without territory."

Gorbachev seems unfazed by Ligachev's stand or by the criticism and challenges from the other end of the spectrum, the radical-reform wing of the party called Democratic Platform. After attending a class reunion at Moscow State University today, Gorbachev answered a reporter's question about the prospect of conflict at the coming party meetings.

Surrounded by security agents and his old classmates, Gorbachev smiled and said, "I fear nothing and no one."

The Moscow party organization has just completed several days of meetings and tonight published a position paper remarkable for its overt attempt to attract new and younger members and to apologize for the "totalitarian and stagnant years" of the past. It said those "anti-democratic structures" were "paid for dearly, in the shape of many human lives."

The Moscow party forms a minority on the newly elected Moscow city government, which is led by the Democratic Russian reformist faction and a radical-economist mayor, Gavril Popov.

The Moscow party, however, adopted a crucial recommendation of the Democratic Platform, calling on the national party to play no role in the leadership of the KGB, the army, factories or internal security police.