Thomas McGlaughlin, an attorney who had worked since June 2012 as a legal-data analyst in Skillman, N.J., for the private company’s Bloomberg Law division, had been seeking to organize about 80 salaried colleagues there since early this year. But the effort, according to an outside organizer with the union, Local 32035 of the Baltimore-Washington Newspaper Guild, has “gone nowhere.”

McGlaughlin says he filed a lawsuit today against Bloomberg LP in state court in Philadelphia, where he lives, claiming that his June 12 dismissal was in retaliation for his organizing activities.

However, Paul Reilly, the Guild representative involved in the Bloomberg effort, says the union has no plans to file an unfair labor-practices charge with the National Labor Relations Board about McGlaughlin’s dismissal. His initial review of the matter, Reilly tells Fortune, suggests “it’d be impossible to prove that it had anything to do with union activity.”

Ty Trippet, a spokesman for Bloomberg LP, where no group of employees has ever voted to join a union, responded via email: “Even after repeated warnings, the employee refused to do his job and repeatedly behaved in an unprofessional manner. This has nothing to do whatsoever with any protected activity.”

In his complaint, McGlaughlin describes a history of “abusive” practices and conflict with supervisors that predated—and he says prompted—his union-organizing efforts, and continued after he began seeking to organize his fellow workers. Among other issues he believes contributed to his dismissal, according to the complaint: In May, McGlaughlin asserts, he reported a company manager to the New York City finance department for having allegedly “incorrectly reported his New York City taxes.” His termination, he concludes, was “retaliatory in nature.” His lawsuit asks for compensatory and punitive damages.

In an interview, McGlaughlin says he had consistently high performance evaluations during his time at Bloomberg Law, an online subscription legal-data service. “It’s only after I started to bring things to the attention of management and advocate for workers’ rights that they started to gin up charges against me.” He says he was paid a little under $70,000 a year, and was fired without any notice or severance. His wife is eight months pregnant.

McGlaughlin blames the failure of the union effort on “the tendency of white-collar workers to identify with management” as well as “the work environment at Bloomberg,” historically inhospitable to unions. A 2004 drive to organize the company’s New York headquarters staff also failed without a vote. The former New York mayor’s business, which employs more than 15,000, has only one unionized business, which was acquired in 2011: the Washington, D.C.-based Bureau of National Affairs. About 700 BNA workers belong to two Newspaper Guild bargaining units.