What most naturally follows?

How to vote against unionization 
Speak out against unionization. 
Before a union can file a petition with the nlrb, it must show sufficient interest in unionization among workers in a designated group. At this point, you potentially have the most power to persuade your coworkers that unionization is not appropriate in your workplace.
The union must specify the group of workers, or unit, it will represent. An appropriate unit is a group of workers who share similar interests and generally perform the same work.