WARSAW -- In a public school classroom last month, a priest and a student squared off. The occasion was the return of religious instruction and prayer to public schools after more than three decades.

"God and church cannot be put aside just for Sunday," the priest told his students at a Warsaw secondary school.

"It's difficult to discuss this with you, Father," a boy shot back, "because you represent the 'company.' "

The use of the word "company" -- once reserved for the oppressive authority of the Communist state -- made the priest wince, but it reflects the changing role of the powerful Polish Catholic Church this year.

For more than 10 years, the Catholic Church was the staunch ally of the Solidarity opposition, sheltering dissidents of all religious stripes and taking on the power of the Communist state. Now Solidarity is the government, and the church has gone from being a political rebel to a very active pillar of the political establishment.

"The church has always had a strong position in Polish society, and now they are trying to get more involved in governing. They are entering a new phase," said a middle-ranking government official.

"We are a Catholic country now, and the Catholic Church has a great influence with people in the parliament and Solidarity," said Solidarity Sen. Zofia Kuratowska.

In recent months, the church has lobbied successfully for extensive changes in the areas of abortion, religious education and family law.

At the urging of the church, the Mazowiecki government has issued new regulations from the Ministry of Health that restrict a woman's access to abortion. The regulations, issued without parliamentary debate, require that she have written permission from four doctors, including a psychologist, before an abortion can be performed.

A list of state psychologists is being drawn up with the church's assistance. The regulations also give doctors employed by government hospitals the right to refuse to perform abortions, an option many have already taken.

Last month, the Catholic bishops issued a letter urging further restrictions, and called on Catholics to support a proposed law that would impose a prison term on doctors, husbands or anyone else who helps a woman have an abortion. This month, members of the Polish Senate tacked onto the bill an amendment that would mete out a two-year prison term to any woman who has an abortion.

One of the senators sponsoring the bill said it is "intended to synchronize the Polish legal code with Christian beliefs."

After energetic lobbying by the church, the Polish Ministry of Education this summer issued hastily drawn up regulations that mandate Catholic religion classes in all state schools. The church is in charge of appointing religion teachers, although the state will have to pay salaries for the lay teachers who will be needed to make up for a shortage of teaching nuns and clergy.

The regulations also give individual schools the option to allow prayer and the display of crucifixes and other religious symbols in classrooms.

Catholic legislators in the Senate also have quietly passed a law intended to make it more difficult to obtain divorces.

Observers credit the regulatory and legal changes to the church's allies in the government and parliament, particularly the Solidarity-dominated Senate, where 75 percent of the senators describe themselves as active or devout Catholics.

Poland's emerging democratic culture also has contributed to the church's clout. As political parties organize and struggle to define themselves and attract support, the church, in a country with more than 90 percent of the population nominally Catholic, is regarded as a potential kingmaker.

"It's very difficult to say something openly against the {abortion} bill. I'm sure there will be great propaganda by the nationalist, religious right against anybody who speaks out," said Kuratowska, a Catholic who is opposed to an abortion ban.

The Mazowiecki government at first was cool to the changes in the education and abortion laws, observers say, but, pressed on its right flank by some of the nationalist and conservative forces positioned around Solidarity union leader Lech Walesa, it later accepted them.

"We have unofficial support from the government, but what can you do with unofficial support?" said a spokeswoman for a Warsaw women's rights group.

A government spokesman at the Ministry of Health said the stricter abortion regulations were issued in part to defuse a parliamentary initiative for a bill that would ban abortion entirely. At the same time the spokesman volunteered that post-Communist Poland is more attuned to Catholic thinking.

"The best example of this new phenomenon is Mr. Walesa," he said. "Those eight children are a new image of the family in Poland."

Catholic Church leaders and parish priests see the church's increasing involvement in legislative politics as a natural extension of its historic role as moral leader in Polish society.

"The schools belong to us because they belong to the nation," said the Rev. Jan Ujma, a Warsaw priest who has been assigned to teach the new religion classes. "If one demands from the church material help and help for the poor and sick, then the church must also be able to participate in other areas of reality."

Religious education and the abortion ban are needed immediately, the church believes, to begin rebuilding a society morally degraded by four decades of communism.

But if the church can now count on its powerful allies in government and parliament, it no longer can count on the automatic allegiance throughout society that it commanded at the height of Solidarity's resistance.

"A year ago the voice of the church was still the surrogate voice for the Polish nation," said one Western observer. "But that is not the case now. The parliament and the government have their own legitimacy. . . .

"You can no longer say that 95 percent of all Poles agree with everything the church says. The church still has an overarching role as the moral glue of this society, but on particular issues, Poles have different views. . . . Now there are competing virtues."

The new catechism classes have been challenged by representatives of Poland's tiny Protestant minority, who said they will foster intolerance toward Poland's non-Catholics, and by the government's ombudsman, who said the new regulations violate a constitutional provision separating church and state.

On the first day of school in Warsaw, some students and their parents were openly skeptical of the church's return to state schools three decades after being banished from state classrooms by the Communists.

"We have been red for too long, but now there is a risk that we become too black," said one student.

The abortion regulations also were pushed through before most women, including members of Poland's fledgling women's movement, knew of them. Even members of the Senate who oppose abortion have criticized the church for pushing an abortion ban before attempting to remedy the country's almost complete lack of contraceptives and contraceptive education.

Opinion surveys show that Polish society is almost evenly split on whether to ban abortion, and politicians and government officials have questioned the church's political acumen in raising such a divisive issue at a time when the country is struggling to maintain the consensus necessary to rebuild its economic and political institutions.

The church itself is divided only on the question of timing.

Last month, at the same time the Catholic bishops were issuing a call for prayer and politicking in favor of an abortion ban, a new Catholic anti-abortion group named after the murdered Solidarity priest Jerzy Popieluszko asked the parliament to postpone the abortion debate, saying it feared that the issue would become a political tool in next month's presidential race.