Poland's independent trade union Solidarity, in an open challenge to the government, said tonight that the union would again shut down all daily newspapers in the country two weeks from now and that a "clash is inevitable on the issue" if communist authorities fail to relax their monopoly on information.

The threat came as printers reluctantly resumed normal work this afternoon following a strike that left most major Polish cities virtually stripped of daily newspapers for the last two days.

In Moscow, the government newspaper Izvestia, in an apparent commentary on the newspaper strike, said today that Solidarity was moving toward seizing state power but that the Polish government can count on the support of its Warsaw Pact allies.

In another development bound to raise the political temperature here, the government announced that the price of bread would be tripled, although no date for the increase was released. Price increases on basic commodities have in the past produced social unrest here.

The announcement was printed in the Communist Party newspaper Trybuna Ludu, which came out in a skeleton edition for the second day today, reaching very few people. The official party daily and the daily newspapers of the armed forces were printed at military facilities here in an attempt to break the strike.

The end of the strike produced conflicting claims about its success. The government said it was a failure and maintained that one-fifth of Poland's normal daily newspaper production of 10 million copies had reached newsstands. The union claimed that the government had "added a few zeros" to the actual figures.

In vowing to continue its struggle for greater and direct access to the mass media, Solidarity said that it would use "the means of pressure" against the government.

"A clash is inevitable over this issue and the government must know that we can organize such strikes any time we want," a spokesman told a news conference here.

He conceded that the challenge was political, saying that "police, the army and the propaganda" were the three mainstays of state authority and that "when you take away one of them each state becomes weaker."

The union wants its own television and radio programs as well as the right directly to answer charges in government-controlled newspapers. "We don't want programs about Solidarity," the spokesman said.

He reported that the printers and other union members were in a militant mood. Many of them, he said, had voted during the night to continue the strike, but were persuaded to abandon temporarily the protest by an appeal from Lech Walesa, Solidarity's leader.

Only printers in the industrial city of Lodz were said to have rejected Walesa's appeal and continue their occupation strike.

The printers in Warsaw were angered when the government attempted to break the strike at the city's major printing plant yesterday afternoon by sending police into the building. The Solidarity spokesman said that an alarm was immediately sent to all major industrial enterprises in the region, which by prearranged agreement were prepared to stage strikes in case the government moved against the printers.

The union had established a special channel of communication for this purpose, he said.

However, the spokesman dismissed a remark attributed to Walesa earlier today that the union was facing "a total and general confrontation" with the authorities. "I don't know whether he made that remark, but if he did that was his personal opinion," the spokesman said.

The union's challenge comes against a background of continued propaganda warfare between the two sides. Solidarity said that talks with the government may resume next week, but added that there was little hope that they would bring about the results the union desires.