Soviet party leader Leonid Brezhnev has pledged that there will never be a return to the "illegal repressions" of the Stalinist era in the Soviet Union, according to a major Brezhnev speech made last month but published today.

In an address outlining the country's new constitution to the Communist Party Central Committee, Brezhnev, without mentioning Joseph Stalin by name, made one of that sharpest attacks on the dictator's use of mass terror that has been heard here in a number of years.

"We know comrades," Brezhev declared, "that some years after the adoption of the current constitution [in 1936] were darkened by illegal repressions, violations of the principles of socialist democracy, Leninist norms of party and state life. This was done in contravention of the constitutional provisions.

"The party has resolutely condemned this practice and it should never repeat."

The millions of arrests, executions and exiles ordered by Stalin made a mockery of the freedoms and protections that the constitution written under his direction had promised. That was one of the main reasons why the Soviets decided 15 years ago that a new constitution, which would not be identified with the dictator's name, should be drafted.

The new constitution, which was announced yesterday, contains the same basic freedoms - press, demonstration, privacy and so on - as the 1936 charter. But it contains an important new caveat which Brezhnev stressed in his speech:

"The rights and freedoms of citizens cannot and must not be used against our social system and to damage the interests of the Soviet people."

That formulation lends legitimacy to the punishment of dissidents whose advocacy of political or social roforms in the Soviet state is officially regarded as subversive.

"Political freedoms," Brezhnev asserted, "are granted in accordance with the interests of the people and with the aim of strengthening the Socialist system."

Nonetheless, Brezhnev's reaffirmation of no return to the use of mass arrests or terror, and even the fact that he chose to deal with the subject, should find a welcome audience among millions of Russians - particularly those who spent long years in Stalin-era prison camps.

The de-Stalinization years of the 1950s and 1960s have been over for more than a decade now, and the sensitive subject of the dictator's excessive is almost never mentioned. The only regular references to Stalin area in connection with his leadership during the war and have been marked by an appraisal far short of the adulation he once demanded, but brighter than the ignominy to which he was for a time consigned.