The ruling, stemming from a complaint against Amazon, bars companies from compelling workers to attend meetings on unionization’s downsides.

The National Labor Relations Board said that so-called "captive audience meetings," which have been legal for decades and are routine during union campaigns, illegally interfere with workers' rights to freely choose whether or not to unionize. Employers ...

After a lengthy consideration, the National Labor Relations Board has ruled that Amazon’s “captive-audience meetings” are a violation of the National Labor Relations Act.

Mandatory “captive audience” meetings in which companies argue against unionization are illegal, the National Labor Relations Board ruled in a case involving Amazon.com Inc., prohibiting one of employers’ most potent weapons against labor organizing campaigns.

The National Labor Relations Board ruled that employers can’t force workers to listen to anti-union speeches, but a Trump board could reverse the decision.

Employers can still hold meetings to express their views on unionization, but must now give workers advance notice and make clear they are voluntary.