A message the opposition says was sent by the office of Gen. Wojciech Jaruzelski to Communist Party leaders in factories restates the authorities' public stance against legalizing Solidarity. But the telexed message left open the possibility of changing the trade union law after talks this month between Solidarity leaders and the government. The message was dated Sept. 26. A Solidarity spokesman today said he was not concerned about the message and Solidarity would enter the talks anyway. He said it was significant that it was addressed to party cells and not to factory managers. ``We are not running away from a discussion about the shape of the union movement, but we think that it must take into account the fact that the union question is an element of a broader problem of the functioning of the political system,'' the message said. Government spokesman Ryszard Straus said today he could not confirm or deny the authenticity of the text, read over the telephone to Western news agencies by Solidarity activists late Thursday. But the official PAP news service later ran a one-sentence report saying the ``secret document'' quoted by Western news agencies ``does not exist.'' The text contained nothing new on the government's position regarding Solidarity, but it underlined the degree of concern over Solidarity chapters springing up openly in many factories on the eve of the promised talks. It urged party leaders to draw pro-Solidarity activists into officially sanctioned unions, giving them proportional representation in official union leaderships and making the official unions reflect workers' demands. At the same time, the message warned against allowing the opposition to make gains of its own on the factory floors. ``The main real danger ... is the rebirth of Solidarity structures as they existed in 1981, that is, as a party of strikes and confrontation. This is what we must all focus our attention on,'' the message said. The government and Solidarity leader Lech Walesa agreed to the talks on Poland's future during a wave of strikes in August. The talks are expected to begin around Oct. 17. The opposition has stressed that the talks must result in recognition of Solidarity, suppressed by authorities since a Dec. 13, 1981, martial-law crackdown. The government has said repeatedly that it will not agree to any arrangement that would bring divisions on the factory floor and that it supports the principle of one union in one workplace. According to the text read by Solidarity, the telex was from Stanislaw Domagala, the head of the chancellory of the party Central Committee secretariat, and was addressed to first secretaries of party committees at the nation's factories. Solidarity spokesmen did not disclose how they received the document.