A group of leading Polish writers has formally protested the dissolution of the country's venerable Writers' Union last month, charging Communist authorities with trying to eliminate "all independent centers of creative endeavor" in Poland.

A 17-page appeal signed by all but one of the 15 members of the presidium of the defunct union was sent to the Internal Affairs Ministry last week. It accused Communist officials of seeking to manipulate union representatives into blacklisting opposition writers and accepting plans for a new, tightly controlled union congress. The union leadership resisted, and the association was ordered out of existence Aug. 19.

The Internal Affairs Ministry announced yesterday that it had upheld the ban and that the decision to terminate the union was final.

Authorities are encouraging the formation of a new union made up of party loyalists and oldtimers. While authors of the appeal did not expect it to bring a reversal, the document is important as a record of the former union leadership's moral defiance and as a warning by some of Poland's most prominent writers against the crushing of artistic freedoms by the government of Gen. Wojciech Jaruzelski.

"Following the decision to dissolve the Writers' Union, unfortunately we have to conclude that behind the decision is a policy to liquidate all independent centers of creative endeavor," the statement said. "This can be proved by the fates as well of other creative organizations."

One member of the union's board, Andrzej Kijowski, predicted a bleak period ahead for Polish writers. "The literary milieu will be split," he said. "Their solidarity will be broken. Writers will be forced to accept new rules. Some will refuse and will be politically marked by this. Others will accept, to get the benefits that come with union membership, but with all the moral costs of such a decision."

Said Andrzej Braun, deputy chairman of the banned union: "The government's decision is likely to undercut the collective influence the union had in maintaining the integrity of Polish culture against Communist dogmatism. It also threatens the material well-being of writers . . . who must rely on membership in the union for health care benefits, pensions and protection from being sent off to state-run forced labor crews as social parasites."

Closure of the Writers' Union capped a campaign purging intellectual and artistic groups of persons strongly in favor of the now-outlawed Solidarity trade union. This has involved the dissolution and replacement of organizations grouping journalists, students, actors and artists. Only the filmmakers' union among the major associations has been spared this fate, and then only after its chairman, the leading director Andrzej Wajda, and several board members resigned under government pressure.

Since its founding 63 years ago, the Polish Writers' Union has been regarded as the nation's most influential organization of creative artists, and the authorities were clearly hesitant about outlawing it. In the end, the writers' board was accused of adopting a program "incompatible with the union's tradition and statutes." It was accused of neglecting the social needs of writers and concerning itself instead chiefly with "creating political alternatives in the system of culture and education."

Despite months of negotiations with party officials to win reactivation of the union after it was suspended when martial law was declared in December 1981, union leaders were surprised by the banning order. They had expected the government simply to dissolve the board, not the whole union, particularly since parliament adopted a new regulation in July allowing for just such an alternative.

Calling the union "the property of generations," the writers' petition says the association had "won unquestionable moral authority in society" by opposing over the years the "opportunistic demands of improvised policies" and by never losing sight of culture's importance to Poland's sovereignty and sense of national identity.

The union had come under fire from Communist officials for not renouncing an alliance signed with Solidarity in September 1981. Critics in the party had also demanded that the union purge itself of outspoken opponents of the government, particularly those who had published their works illegally in the underground or emigre press or had cooperated with "anti-Polish subversive centers" abroad.

The Polish leadership was especially incensed that the union had not expelled Zdzislaw Najder, a specialist on Joseph Conrad who also heads the Polish section of Radio Free Europe, and more than 30 other members publicly cited for agitating against the state. Party officials accused these writers of turning the literary scene into a battleground for political confrontation.

"What is at the heart of the matter," Waldemar Swirgon, Communist Party secretary for culture, said in an interview in July, "is for the Writers' Union not to be used as a political instrument but to deal with the problems and needs of writers. This has nothing to do with limiting the scope of Polish literature."

The paradox in such a remark is that writers' unions throughout the Soviet Bloc were initially set up to be ideologically oriented and to engage in political debate. This objective assumed, of course, that the unions would not veer from party lines. Polish union officials say the dissolution order was "unjustified and inconsistent with the law on associations."

"Claims of the union's antistate activities cannot be confirmed in any documents or public activities," the union leadership asserted in its appeal. "If stances and statements of some union members qualify as inconsistent with the obligatory doctrine of the political system, the specific nature of the writers' profession should be taken into account. Conformity in convictions and attitudes is tantamount to betraying the vocation."