MOSCOW, AUG. 6 -- Yegor Ligachev, the voice of conservatism within the Soviet leadership, warned today that the ruling Communist Party may be going too far with the country's political, economic and social reforms and, as a result, may be departing from socialism.

Ligachev, 67, who ranks as number two in the Kremlin hierarchy after Mikhail Gorbachev, the party's general secretary, objected strongly in a speech published today to the introduction of market forces as a decisive factor in the Soviet economy as advocated by some reformers.

Ligachev appeared to have taken advantage of his first opportunity to speak authoritatively while Gorbachev was away from Moscow on his annual summer holiday, some Soviet political observers noted, wondering whether there was a deepening split in the country's leadership.

Ligachev demanded that strict limits be observed on the process of political democratization and denounced recent demonstrations and strikes as undermining the country's order. The increased freedom here, he said, was not intended to allow development of a political opposition or a multiparty system.

And he reemphasized the "class" character of Soviet foreign policy, saying that "any other presentation of {international} questions just sows confusion among Soviet people and among our friends abroad.

"Actively joining in finding solutions to common human problems in no way means any artificial slowing down of the struggle for social and national liberation," he said, declaring Soviet solidarity with "workers of the entire world."

Ligachev, whose speech to Communist Party officials in the city of Gorky was published in the party newspaper Pravda, also declared that the country's achievements under socialism cannot be questioned, though some leading political scientists, economists and historians have asserted that the Soviet system cannot even be considered socialist because of its severe shortcomings.

His speech, which was reported extensively on state television and radio, was particularly notable for its return to classic Soviet political assessments and formulations after months of the often-challenging changes of Gorbachev's "new political thinking."

Ligachev, however, appeared to be more concerned with marking the limits of what he regards as acceptable reforms and with controlling the pace of perestroika, as the reform process is known, than with directly challenging Gorbachev's leadership or opposing the changes he is introducing.

"He uses all the right words -- democratization, socialist pluralism, even anticonservatism," one Soviet journalist, a declared reformist, commented. "But in Ligachev's mouth they have a totally different connotation."

"This is not the first time that Gorbachev has gone away and Ligachev has spoken out," a university professor commented, "and in the past this has signaled a major confrontation over very substantial issues within the leadership.

"So, the main thing may be not so much what Ligachev is saying -- his position is well known, and it changes little -- but that he is speaking out again. . . . And so we ask whether a showdown is coming at the top."

But other analysts believe that Gorbachev tolerates such public questioning of his policies to contain conservative opposition to the reforms. By allowing Ligachev to voice the doubts, misgivings and criticism that many of the 20 million party members have, Gorbachev may be hoping to reassure them that their views are considered within the country's leadership.

Gorbachev, when questioned two months ago about divisions in the party leadership, repeatedly denied that there were any sharp differences and, in the face of earlier reformist criticism of Ligachev, he defended his conservative number two as loyal to perestroika.