The article discusses selected issues of legal regulation of relations between trade unions and employers. The author touches upon some aspects of internal relations within unions, as corporations, and concludes that granting trade union members with the right to challenge the Trade Union decisions in cases stipulated by law, in particular, when the rights of workers are being breached. Given the public nature of collective agreements, the author justifies the opportunity to challenge the provisions of collective agreements that violate the rights of third parties. The author supports the suggestion made by T.A. Soshnikova on enshrining the right of Trade Unions to appear in court in order to protect the rights and freedoms of their members. In connection with the extension of the scope of work of employees temporarily assigned to other parties under contracts for the provision of personnel, the author justifies the necessity of disseminating the provisions of the collective agreement for this category of workers in order to prevent the infringement of their rights.