WARSAW, SEPT. 6 -- The Solidarity labor union has prohibited use of the movement's familiar red logo by Poland's most widely read daily newspaper, Gazeta Wyborcza.

The union's national leadership said it voted the ban because the independent, pro-Solidarity daily is biased against union chairman Lech Walesa and no longer serves the union's interests.

Gazeta Wyborcza -- Polish for Election Gazette -- has a daily press run of 350,000. Under editor-in-chief Adam Michnik, a historian and former political prisoner, it has supported the government of Prime Minister Tadeusz Mazowiecki and criticized Walesa's political ambitions.

The move to strip the logo from the paper's nameplate is the latest salvo in Walesa's increasingly aggressive bid to win the Polish presidency. It also signals the disintegration of the old Solidarity alliance of industrial workers and intellectuals into competing political camps.

Union spokeswoman Barbara Malak resigned in protest of Wednesday's decision, saying Walesa was using the Solidarity logo as a censorship tool.

Walesa told Polish television tonight that while "everyone" in Solidarity had fought communism together, "it's time we start bearing our own banners and our own signs to identify ourselves."

The decision of the union's national council was far from unanimous. The council voted 26 to 21, with 12 abstentions, in favor of the ban after refusing to hear spokeswoman Malak's arguments against it.

Gazeta Wyborcza's editorial board said the paper would abide by the ban, although the editors questioned Walesa's right to deprive them of a word that has come to be associated with the nation's anti-communist spirit.

The newspaper removed the logo, and the phrase "There is no Freedom Without Solidarity," from its familiar spot on the left side of the front page today and used it as a headline over an editorial explaining the ban:

"We are not convinced that {Solidarity} has an exclusive right to decide about our common sign. However, out of respect for the union and its authorities, we are not going to debate that point."

Gazeta Wyborcza was founded in the hectic month before Poland's historic, quasi-democratic parliamentary elections in June 1989 and served as Solidarity's campaign chronicle and trumpet. The staff was drawn from underground opposition newspapers around Poland, and the newsroom is still housed in an abandoned kindergarten building.

Walesa first took aim at Gazeta Wyborcza in June, declaring that it was part of a "a war at the highest level of government" against him and calling on Michnik to step down as its chief editor.

After Walesa complained that the paper frequently edited his comments to make him look bad, Gazeta editors responded by publishing his remarks in unedited form, which many readers found nearly incomprehensible.

The paper is not above political sniping, quickly informing readers of Walesa's purchase of a small house for his married son but failing to note that Michnik had bought an apartment for his wife near Gdansk.