Poland's national legislature today voted to give the government emergency powers during a transitional period toward the lifting of martial law, despite strong protests from the Roman Catholic Church about several details of the new law.

A second vote in the legislature, known as the Sejm, gave the 18-member collective state presidency the right to "suspend" martial law or reinstate it at any time. Officials already have said that military rule is likely to be "suspended" by the end of this year and about 200 remaining political prisoners released.

The church's objections to the new emergency law were spelled out in a confidential letter to the Presidium of the Sejm signed by the primate of Poland, Archbishop Jozef Glemp, and the secretary of the Bishops' Conference, Archbishop Branislaw Dabrowski. The closely argued four-page memorandum was sent Thursday in the name of all Polish bishops, and a copy was obtained by western journalists today from sources at the Sejm.

In their letter, the tone of which is much stronger than the church's public statements, the bishops said that many of the passages in the draft bill aroused "doubts, reservations, or even opposition" from a moral point of view.

He suggested that passage of the bill could further undermine the "credibility of the authorities" because in some cases it introduced possibilities of even sharper legal repression than that applied under martial law.

The law passed today, with no votes against and only nine abstentions, contains some minor modifications to the draft introduced Monday. But the changes do not meet the substance of the episcopate's criticisms.

Once martial law is "suspended," the government will no longer have the automatic right to intern people without trial, impose a curfew, regulate citizens' movements within Poland, ban all kinds of public gatherings and protests or forcibly take possession of private apartments or the produce of private farmers. This has enabled the authorities to present the legislation as a major step toward "normalization of everyday life" and the ending of military rule.

The critics have argued that many of these legal powers were in any case being phased out. The new legislation enables the government to refine and in some ways even increase its controls over the population.

A legal adviser to the outlawed Solidarity trade union estimated that, even with the ending of preventive internment, between 3,000 and 5,000 people will remain in prison after being convicted of violating martial law. They will be allowed to apply for clemency individually.

In their letter, the bishops complained that during "the period of suspension of martial law" workers in many key industries will not be allowed to resign without the agreement of management. They said this regulation put a worker in the same position "as a peasant in feudal times" who was legally attached to the soil by his masters.

An amendment to the draft has given workers the right of appeal against the manager's decision, but the principle of government-directed labor remains intact.

The bishops attacked several "imprecise" new regulations that they said provided a pretext for "unjust and arbitrary decisions." They particularly criticized a new clause written into the penal code that provides for a sentence of up to three years imprisonment for anyone "who undertakes action with the aim of causing public unrest or disturbances."

"Such elastic formulas can only lead to the creation of a kind of psychological terror," the letter said.

The bishops argued that some of the new regulations actually sharpened martial-law rigors while the government proclaimed that they were being softened. Entirely new penal sanctions had been introduced into the labor code, they said, and a wider range of factories subjected to special repressive measures.

The letter also complained that, although "suspension of martial law" is meant to last for a temporary period only, several repressive new provisions had been introduced permanently into the penal code. These included a clause giving the public prosecutor authority to bug telephone calls and monitor private correspondence without notifying the person involved and to use it as evidence in court.

The bishops described this regulation as contrary to constitutional guarantees for the secrecy of correspondence and said that it created a new category of crime.

Several new regulations, the bishops said, undermined important reforms that the government had introduced. As an example, they described as "purely decorative" the reactivation of workers' self-management in industry since the new workers' councils can be dissolved at any time and their right to elect managers also has been suspended. The letter also attacked clauses in the new law that allow workers or students to be expelled from their factories or colleges immediately if they take part in strikes or demonstrations. This legalizes a practice that has become widespread in Poland during the past year.

The bishops said they were motivated by "the best intentions: the maintenance of social peace and the credibility of the authorities in society. We ask for our letter to be read and accepted in such a spirit," they concluded.