MOSCOW, JAN. 12 -- Soviet leader Mikhail Gorbachev has admitted that his program for economic and social change is under attack from all sides of Soviet society but warned that to stop now would be to kill the country's last chance for reform, the official news agency Tass reported today.

Speaking to a group of top media and cultural figures at a meeting Friday, the Kremlin leader said that ideological disputes, economic uncertainties and social adjustments are to be expected as the Soviet Union undergoes radical change under his program of restructuring, called perestroika.

"If perestroika is indeed the continuation of the revolution, if we are currently pursuing a revolutionary policy, then struggle is inevitable," he said.

While acknowledging that "tangible positive results" from his program are still in the future and issuing a pointed call for restraint by the more reform-minded segments of the Soviet press, Gorbachev cautioned against any backsliding. "If we stop the emerging processes, get frightened by them, this would have most serious consequences, for we will not be able to mobilize our people for an undertaking of this scope one more time."

Gorbachev's day-long meeting at the Communist Party Central Committee with the group of top editors and artistic leaders was timed to the "second stage" of the reform process that began Jan. 1 with the introduction of major new economic reforms.

The carefully balanced speech, to be published in the official press Wednesday, is his most detailed acknowledgement of the struggle taking place here now as liberals and conservatives fight to stake out positions in debates over history, literature, economics and politics.

The meeting was attended by Yegor Ligachev, the second-ranking member of the ruling Politburo in charge of ideology, but not by Alexander Yakovlev, the Politburo member who handles propaganda. Various Soviet sources have described Yakovlev as being either ill or away on a holiday, but his absence was viewed as unusual, given the intensity of the debates. Ligachev is seen as the Kremlin's leading conservative voice, while Yakovlev is viewed as a key advocate of domestic reforms.

Gorbachev, the leading reformer on the Politburo, called for more caution on the part of some newspaper editors, an appeal that seemed directed at publications that have been pushing the limits of glasnost, or openness in debate.

"No one is outside control in our country," he said. "This applies to the mass media. The Soviet press is not a private shop."

The Soviet leader again served notice that open debate is permissible only within the bounds set by the party. "We are for openness without reservations, without limitations, but for openness in the interests of socialism," he said.

While not naming names, he said editors should have "a sense of responsibility," and called on all sides in the press and literary debates to keep their heads and their dignity.

"One should be above personal emotions and attitudes and should give priority to the interest of perestroika," he said, remarking on the epithets that have been hurled in recent arguments.

Gorbachev referred indirectly to the firing of Moscow party boss Boris Yeltsin, which last November presented the Soviet leader with his first political crisis and the Soviet public with the first clear sign of a split in the leadership.

For the first time, Gorbachev acknowledged the political impact of Yeltsin's dismissal and public humiliation. The episode caused widespread and unexpected discontent, as informal political groups and students called for a more open discussion of Yeltsin's faults, in particular his still-secret speech at a Central Committee meeting Oct. 21.

Gorbachev, who backed Yeltsin's ouster, accused his former outspoken ally of lacking "composure" and of employing " 'ultra-perestroika' phraseology" that proved "useless."

"We shall not conceal the fact that the party's rebuff to this phraseology was viewed by intellectuals, especially young people, as a blow to perestroika," Gorbachev said. "This is the greatest delusion."

Preserving the balance he has struck in the wake of the Yeltsin affair, Gorbachev also criticized conservatives, saying that those who argue that the reforms are undermining the "foundations of socialism" are afraid of giving more authority to the people.

In exhorting people to rally behind perestroika, Gorbachev was prodding not only party leaders and government bosses, but also workers. It was one of his first public acknowledgements that opponents of perestroika include ordinary people who will now have to work harder.

"Deplorably, a widely current attitude is that one can work 10 times less, a hundred times less than another, can do nothing at all and at the same time enjoy all the benefits to the same degree as people who by their work make a large contribution to the country's development," he said.

Gorbachev's speech, which was followed by a discussion among the media executives, was delivered in the now familiar Gorbachev style -- at times schoolmasterish, at times exhortatory, even pleading, and interspersed with specific examples.

On the highly politicized issue of Soviet history, Gorbachev sided with the liberals, welcoming the revelations that have recently been pouring out in the Soviet press. He said the "deepening knowledge, understanding of history and drawing of lessons from the past" had "enriched the entire political, ideological and spiritual sphere of the society's life."

Gorbachev called for further historical research, and indicated that his report at the 70th anniversary of the Bolshevik Revolution last November should not be viewed as dogma. He also said a commission established to study the era of former leader Joseph Stalin will publish its results by the summer.

He said he could not "agree with those who suggest that we forget history or use only a certain part of it." Ligachev has seized on the continuing debate about the past to attack those who dwell on its negative periods.

Many of the themes in Gorbachev's speech were familiar, but this time he gave them a sharper edge and, in some cases, defended them from attacks.

"We are frequently criticized, by some from the right, some from the left," he said.

Gorbachev returned to his argument that without the "democratization" of Soviet society, reforms will founder. He said that next summer's Communist Party conference will further extend democracy within the government, within the party and within the judicial system.

Gorbachev criticized the widespread and growing resentment of people who earn more than an average wage -- an openly debated issue here as workers' wages become linked more closely to productivity and as the semiprivate cooperative sector begins to get off the ground. Gorbachev noted, for instance, that 13,000 cooperatives have been registered and 300,000 people have become self-employed.

At the end of the meeting, Gorbachev outlined progress achieved in the first two years of the program, citing an increase in resources spent on housing, health and other social services. He noted an improvement in mortality figures, largely the result of the campaign against drunkenness.

But he acknowledged that goods are still in short supply and that the economy is in a tight bind, squeezed by losses in revenues because of the drop in oil prices and the loss of alcohol sales. The Soviet people, he said, are "in for big work."