Poland's powerful Roman Catholic Church, in an unusual statement, criticized "irresponsible" antigovernment dissidents yesterday in an apparent effort to prevent labor unrest from provoking the Soviet Union into military intervention.

The communique put the church hierarchy, traditionally a nationalist power competing with the communist government for the nation's loyalties, into the unexpected position of urging the predominantly Catholic population to cooperate with authorities and turn away from the most extreme appeals for increased liberalization of the Soviet-backed system.

The hierarchy, in its statement and an accompanying briefing for correspondents in Warsaw, strongly indicated it acted out of concern that the months of labor unrest that have shaken Poland and worried its Warsaw Pact allies could lead to Soviet-led military action and restrictions on Poland's "freedom and statehood."

The Polish government, meanwhile, ordered Associated Press correspondent Steven H. Miller to leave the country by midnight tonight, citing unspecified articles he wrote about the Polish crisis. Unless the orders are rescinded, Miller will become the first American reporter known to have been expelled since the labor unrest began more than five months ago.

The expulsion order follows several days of complaints in the official Polish press that Western reporters are exaggerating the effect of Poland's labor unrest and the danger it presents to order under the communist government. The Rev. Alojzy Orszulik, a church spokesman explaining the hierarchy's statement, joined in this criticism yesterday, saying Western news reports of a possible Soviet intervention have created panic among Poles.

But Father Orszulik said the church statement was aimed particularly at the dissident Self-Defense Committee and the anti-Soviet Confederation of Independent Poland, which he said were making remarks interpreted as calls for overthrow of the country's communist system. He did not specify Solidarity, the independent labor union federation that has spearheaded most of the current agitation.

"We have in mind mainly those noisy and irresponsible statements which have been made against our eastern neighbor," he said, according to Reuter, in an obvious allusion to the Soviet Union.

The statement itself also made transparent references to fears of Soviet intervention, calling on Poland's Catholics to use moderation so "the whole nation" accepts the current "national renewal."

"A firm will is necessary to counteract all attempts to stop the process of national renewal, to put the community at variance and use the existing troubles for goals alien to the good of the nation and the state," said a text of the statement transmitted by The Associated Press.

"It is forbidden to undertake such actions which could expose our motherland to the threat of endangering freedom and statehood. The efforts of all Poles must be aimed at strengthening the initiated process of renewal and at creating conditions to fulfill the social contract between the authorities and the community."

The communique, issued after a meeting in Warsaw of the Polish bishops, especially urged restraint at ceremonies marking the anniversary next Tuesday of riots along the Baltic coast in December 1970. Polish authorities are taking care to keep the observances from getting out of order and the church statement suggested that they should "end a period of painful experiences."

In Moscow, the Soviet news agency Tass said the United States is encouraging "antigovernment and antisocialist elements" in Poland and using the unrest there to pressure its NATO allies into increased military readiness against the Soviet Union.

"The Carter administration is intentionally dramatizing the situation in Europe, whipping up a state of psychosis in the mass media in order to advance its plans of building up NATO araments," the official agency said.