The National Labor Relations Board extended the time period for the public to weigh in on whether to keep, modify, or revoke a 2014 rule that streamlined the path to a union election for workers who want to organize.

The board said Jan. 26 that it would accept responses to its request for information on possible changes to the rule until March 19. The original deadline was Feb. 12.

An NLRB majority consisting of then-Chairman Philip A. Miscimarra (R) and...