The House Education and Workforce Committee voted along party lines to pass a bill that would overwrite a 2011 ruling by the NLRB. The rule, which was implemented in April 2015, allowed employees to vote on union representation 11 days after filing a petition and gave employers 7 days to object to the NLRB. This was controversial many believed the time frames given in the ruling were not sufficient for employees to communicate amongst each other and with their employers and was thus referred to as the ‘ambush election’ rule. The bill also overwrote the NLRB ruling that allowed employees to form micro-unions, which some claim have fragmented unions and made things unnecessarily complicated for employers. Opponents of the new bill have criticized the mandatory 35-day waiting period because it will make it more difficult for unions form or win elections.
See "GOP bill to roll back labor relations board rules advances in House", Lydia Wheeler, The Hill, June 30, 2017