WARSAW, JUNE 6 -- Pope John Paul II's third visit to his native Poland, to begin Monday, may mark the beginning of a new era in relations between the Roman Catholic Church and communist states, based on increased church stability in Poland and the opening of new channels here between Moscow and the Vatican, government and church officials say.

During seven days in the country, the pope is expected to act and speak for Poles' political and national aspirations as he did during his last visit here in 1983, when the nation was ruled by martial law. But church officials say the 67-year-old pontiff also will be seeking to build on a broader Vatican policy of accommodation with the East Bloc and its dynamic new Soviet leader, Mikhail Gorbachev.

Relations between the Polish church hierarchy and the government of Gen. Wojciech Jaruzelski have been remarkably smooth in the run-up to the pope's visit. The two sides have agreed with relative ease on potentially controversial elements of the papal schedule, such as his meeting with Lech Walesa, chairman of the banned Solidarity trade union, and trip to the gravesite of slain pro-Solidarity priest Jerzy Popieluszko.

At the same time, Vatican and Polish church and government officials have been working toward historic agreements that could establish the first full diplomatic relations between the Vatican and a Soviet Bloc government, grant the Polish church full legal status for the first time in 40 years of communist rule and expand the church's social and economic activity.

None of the prospective accords is expected to be announced during the pope's visit. But church officials here say they could shape the mood of John Paul's contacts with government officials and messages to Poles at a time when the Vatican is thought to regard expanded contacts with the East Bloc -- and an eventual papal pilgrimage to the Soviet Union -- as key goals.

"What is happening here is in some sense a preparation for improved church relations with all of the East Bloc," said Macin Krol, a prominent Catholic editor. "And so that is something the pope is likely to address."

Poland's political impasse, and the church's continuing role in defending the remnants of Solidarity, may prove the counterpoint to the emerging dialogue, other observers here say.

Although few expect the pope's appearances to be charged with the same political tension as those of four years ago, Solidarity's underground temporary coordinating commission has called on Poles to bring union banners to masses, and police have responded with public and private warnings that such "disturbances" will be suppressed.

Walesa and other Solidarity leaders say they hope that the visit will renew the sense of national purpose created by the pope's first visit in 1979, a mood that later proved crucial for the formation of the independent trade union in 1980. "It will give us the opportunity to do something together in mass, to have this feeling of cohesion and mutual support," said Janusz Onyskiewicz, a Solidarity spokesman. "That is terribly important for Solidarity."

Several of John Paul's acts will be symbolically supportive of national aspirations and Solidarity's ideals. In addition to his planned meeting with Walesa Thursday in Gdansk, the pope will pray at the grave of Popieluszko, a pilgrimage point for Solidarity supporters around Poland, and meet with a large group of opposition and church cultural activists at another Warsaw church.

Church officials say John Paul also may make an impromptu stop in southern Poland at the grave of Otto Schimek, a Wehrmacht soldier shot for desertion during World War II who has been adopted by some Catholics and by Poland's fledgling independent peace movement as a hero of conscientious objection. Authorities reject the Schimek movement, and police have broken up attempts by groups to visit the grave in the past.

Above all, liberal church activists hope that the pope will strongly take up the demand for free association and the expansion of pluralism, as advanced by Polish bishops in several strong declarations last year. "The hope is that the pope will speak on this issue and advance it," said Krzysztov Sliwinski, a Catholic writer.

All of these activities could irritate and embarrass communist leaders, who clearly hope to use the trip to consolidate the "normalization" carried out since 1982 and the recent advances in Jaruzelski's international acceptance. John Paul, government spokesman Jerzy Urban said last week, should talk about "the defense of peace, the growth of national optimism and of the unity of Poles and against various vices . . . like alcoholism."

While the pope's statements will surely not fit this mold, both the church hierarchy and government officials appear ready to play down their longstanding political conflicts in favor of the broad new agreements now on the horizon. Only a swelling of spontaneous popular enthusiasm for Solidarity and subsequent confrontation with the government in the course or aftermath of the pope's visit could easily undermine this new trend, government and church officials say.

The chief elements of the new stage of relations are the prospective establishment of full diplomatic relations between Warsaw and the Vatican and the enshrinement of the Polish church's privileges and powers in law. The two steps have long been linked in negotiations, although the Polish primate, Cardinal Jozef Glemp, recently hinted that they may occur separately.

For the Polish church, the two moves could have the effect of stabilizing and consolidating the church's role and lead to the return of key institutions, like the Caretas charity network, seized by the state during the Stalinist era.

However, some Polish bishops believe the moves -- particularly the establishment of relations with the Vatican -- could increase the risk of state interference in church affairs. "Relations with a Vatican led by a Polish pope sound great," observed a western diplomat, "but no one is sure if in the long run the state might try to use the Vatican to go over their heads here."

The Polish communist leadership, which has long sought the Vatican ties, believes that the link could strengthen the legitimacy of a government with scant public respect and give Warsaw the chance to play a key role as a link between the Vatican and Moscow.

For Jaruzelski, the first landmark step toward these goals came last January, when he became the first East Bloc communist leader to be received by a pope in the Vatican. Both leaders called the event "historic."

Since then, Vatican and Polish officials have shuttled between Rome and Warsaw to hammer out the details of an agreement on full diplomatic relations. Although no public announcement has been made, a joint commission of Vatican and Polish church officials has been set up to oversee the final agreement, sources said.

A senior church official recently told Catholic activists that the establishment of relations could be expected within a few months, the sources added. The principal difficulty could be snags in reaching a parallel agreement over the legal status of the Polish church and the overall reluctance of some Polish bishops to accept the deal, they said.

Vatican sources close to Cardinal Agostino Casaroli, the Vatican's secretary of state, have expressed caution about a quick resolution of the issue of diplomatic relations, saying there is still much to be negotiated.

They point out that as a former cardinal from Krakow, John Paul is very aware that formal diplomatic relations could weaken, rather than strengthen, the role of the Polish bishops, because a papal nuncio would become the government's chief interlocutor with the church.

But what may soften the pope on this issue, according to the Vatican sources, is the prospect of using an accord with Jaruzelski as a lever to improve church relations with the Soviet Union, which the pope has privately made clear he would like to visit in 1988.