Poland's independent trade union, Solidarity, today accused the government of breaking labor agreements signed earlier this year and made clear it will resist waht it regards as a new government offensive against its activities.

Solidarity's national committee, at a meeting in the Baltic port of Gdansk, also formed a committee to secure the release of political prisoners. Although a statement issued after the meeting strongly indicated the union does not intend to back down, its overall tone remained relatively restrained, and there was no threat of further strikes.

Industrial unrest in Poland has subsided over the last week with the country's communist authorities launching a full-scale campaign for harder work and tighter industrial discipline. In their latest statement, Solidarity's leaders have attempted the difficult balancing act of pacifying their own militant rank and file while preserving the present fragile state of social peace.

Both sides in Poland's crisis are eager to keep passions from getting out of hand before the 10th anniversary next Tuesday of workers' riots along the Baltic coast in December 1970. Considerable effort is being made to prevent ceremonies in Gdansk and Szczecin, planned to commemorate at least 50 workers killed when police opened fire, from providing yet another flashpoint.

In its resolution, Solidarity said it was not concerned with evaluating the opinions of the political prisoners whose release ws originally demanded by the union's Warsaw branch nearly three weeks ago. But it said the prisoners, who include an extreme right-wing nationalist, Leszek Moczulski, should be freed if confidence is to be restored between the authorities and the people.

The resolution also called for the halting of all "repressive actions." The nine-man committee on political prisoners will be headed by Solidarity's leader, Lech Walesa. But there has been no indication whether it will be able to open formal talks with the government.

Talks on the demands of the union's Warsaw branch, including a call for reduction in the power of the security services, began last week, but have since been quietly suspended. It was a threatened general strike over the issue in the Warsaw region that originally triggered the present state of political tension.

The dilemma facing Solidarity is that if feels the need to maintain constant pressure on the government to prevent the slow erosion of its gains over the last few months. But this friction itself results in general political instability and tension at a time when Poland is under ever closer scrutiny by the Soviet Union and its allies.

Another potentially dangerous issue is the suspension from public showing of a film devoted to the negotiations in Gdansk last August that resulted in the establishment of independent unions. The film, "Workers 80," was scheduled to be shown in several Warsaw cinemas earlier this week. But, at the last moment, a high-level decision to allow its screening was reversed.

The film was attacked in the Communist Party newspaper, Trybuna Ludu, as an inaccurate account of what really took place in Gdansk since it concentrated too much on conflict rather than conciliation. The newspaper demanded cuts and "completion."

Solidarity's national committee today strongly protested against the ban on the film, arguing that it brought into question the government's "professed aim of renewal." I said the decision to withdraw the film, after its showing had already been announced in the press, "will deepen the present crisis which is above all a crisis of confidence."

A delegation from Solidarity is due to discuss the issue with the minister of culture. Once again, the episode illustrates the difficult position of Solidarity's leaders since several of the union's own branches are known to have called for strikes unless the film is shown.

Solidarity also made clear it will refuse to bow to the campaign mounted by the authorities, and strongly supported by the Soviet bloc, for a purge of "anti-socialist elements." The statement rejected "talk about the menace of counter-revolution" and said it would not allow the division of its union members into "good and bad."