WARSAW, JAN. 19 -- The Polish government today indicated it was preparing to make an important concession to the country's political opposition by creating the Warsaw Pact's first program of alternatives to military service for conscientious objectors.

The move follows a sustained campaign here by the dissident group Freedom and Peace for the right to refuse military service and a growing trend of conscientious objection in communist-ruled Eastern Europe.

Government spokesman Jerzy Urban said at a press conference that military authorities were considering a plan to allow Poles to refuse military service on condition they serve in civilian posts for twice the normal military term, which varies from two to three years.

Urban also said that if the plan is adopted, courts could reconsider the cases of Freedom and Peace members imprisoned for refusing to enter the military. Ten such dissidents have been jailed in recent months.

The Polish plan, which Urban compared to alternative service programs in such western countries as West Germany and France, would be the first in the Soviet-led Warsaw Pact to allow youths to choose service outside the military. Currently, Poles can qualify for alternative service only on health grounds and then only with the consent of military authorities.

Hungary and East Germany have strictly limited programs that allow conscientious objectors to serve in unarmed military construction units. In Hungary, the waiver is usually only granted to members of the Jehovah's Witness religious group. Conscientious objectors in both countries are regularly imprisoned, and alternative service has become a key demand for dissident groups there as well as in Czechoslovakia.

Representatives of conscientious objector groups from several East Bloc countries met in Budapest last year to coordinate strategy for activity in the Warsaw Pact, which committed itself to providing alternative military service in the 1975 Helsinki accords.

According to Polish activists, a conscientious objector movement is nascent in several areas of the Soviet Union, which does not recognize conscientious objectors or provide any alternative service.

Under the new Polish policy, Urban said, youths could reject military service out of "ideological convictions and attitudes." They would be assigned to hospitals and other public institutions, he said.

Polish leaders of the conscientious objector movement welcomed today's announcement but said the plan outlined by Urban is insufficient.

"We are talking about five years of unpaid labor the government is demanding from conscientious objectors," said Jacek Szymondeski, a prominent Freedom and Peace activist. "Obviously we will be against this provision."

But, Szymondeski added, "I think many people will prefer alternative service even if it will mean four or five years, because conditions in the army are so bad."

Political activists here said the proposed policy may have been designed to slow the rapid growth of Freedom and Peace. Since its founding in 1985, Freedom and Peace has emerged as one of the country's most aggressive dissident groups and as a vehicle for a new generation of young opposition leaders.

Freedom and Peace has been the object of vitriolic attacks in the press by Polish military leaders since its founding and has been declared illegal by the government. When Gen. Wojciech Jaruzelski, head of the Polish state and leader of the Communist Party, was asked about the group in a televised meeting with youth late last year, he scornfully referred to those who refused military service as "wimps" who have rejected their duty to the nation.

Urban said Poland has not changed its official view of Freedom and Peace, which he called an "antinational" group intent on weakening Poland's defenses.