Poland's dispute over the display of crucifixes in schools has brought the Roman Catholic Church and the Communist government uncomfortably close to their most serious confrontation since the imposition of martial law in 1981.
A week ago, when the issue was sparked by the authorities' removal of crosses in the agricultural school at Garwolin, it seemed that the controversy might be contained as a local issue - one that could be settled without too grave an upset in church-state relations.
But a statement by the bishops' main council, which met almost immediately after Poland's Jozef Cardinal Glemp returned from a tour of South America, gave the dispute a new and potentially dangerous national dimension.
The statement was a firm declaration of support for the Garwolin clergy and the protesting students. The bishops adhered to the claim by the church to display religious symbols in public places and institutions such as schools. ''The crosses (in the Garwolin school) should be restored,'' they said, ''and the rights of Roman Catholics respected.''
The message was read at a crowded mass at which Bishop Jan Mazur told the congregation, ''The church is not leaving you. The good of the country requires calm and peace which can only be achieved by respecting the basic rights of Catholic society and individuals.''
Only a few hours previously, the government spokesman, Jerzy Urban, had told his regular Tuesday news conference that the authorities would not ''resort to drastic measures.'' But, he said, it would insist on crucifixes and other religious symbols being kept out of public buildings.
His comments on this latter point seemed quite uncompromising. But the assurance suggested that the government was relying upon the church leadership to defuse the protests at Garwolin within the framework of the Polish Constitution's call for separation of church and state.
The government, Urban said, did not want ''a war of crosses,'' but the crucifixes would have to be taken down. The state, he added, did not ''try to secularize church buildings,'' and the church should not ''try to clericalize state buildings.''
But the unequivocal nature of the stand taken by the bishops suggests that the leadership of the church is no more disposed than the local clergy to back down. Thus, what was thought last week to be a situation brought about by overzealous local officials has brought church and state to a new standoff which could have damaging effects for both.
The church itself has much at stake, including, for example, the opportunity it has had in the last year to build new churches on a scale unprecedented in postwar Poland. At this point, no fewer than 900 churches are being either built , reconstructed, or enlarged.
And recent statements from both church and government officials seem to indicate that a resumption of the diplomatic ties between Warsaw and the Vatican - broken off after World War II - is now within the bounds of possibility.
This, of course, is closely connected with the church's longstanding attempts to secure government recognition of its place in Polish society. It hopes that the government will make some concessions on this score in return for this important diplomatic tie.
For the government, any enlargement now of this sudden conflict over school crucifixes could not not have come at a more embarrassing time.
Since the beginning of the year, the regime has intensified its efforts to win greater national unity and credibility. It has, moreover, had considerable support from the primate in his moves to restrain radical priests whose outspoken sermons about Solidarity and political prisoners had angered the authorities.
Glemp has come under criticism from within the church on this score - notably for his removal of one particularly militant Warsaw priest to a rural parish. But he obviously thought it wise to avoid lesser sources of friction for the church's own interests, as well as for domestic peace and harmony.
For its part, the ruling Communist Party needs all the tacit support Glemp might generate among moderate Catholic opinion for the government's program of social and economic reform. Glemp could also help move people to put in a bigger work effort. This is needed to recover from the devastating effects of four years of social conflict.
This week, the party is on the eve of a national conference in which it will try to persuade Poles of the sincerity of its pledge to carry through the basic reforms of the 1981 ''democratizing'' party congress.
Martial law cost the party a million members. But it now claims to be both a restructured, stronger party, and one firmly committed to the genuine implementation of the ''renewal'' program.
The privileged position of the Polish church compared with churches elsewhere in Eastern Europe has always been a sore point with the Soviets. Most of the Poles believe, therefore, that the firm official stand over religious symbols is meant as a demonstration to hard-liners that the authorities are capable of holding the line on any ''liberties'' taken by the church.
After their respective statements Tuesday, both sides seem to be dug in on positions which will make compromise difficult. A standoff could mean the church would have less leeway. But it would also undermine the government's efforts to improve its public image.