In landmark guidance, the federal commission created to fight racial and sexual discrimination declared Monday that employers that fail to use a worker's preferred pronoun or refuse them the chance to use the restroom of their choice will be engaging in prohibited harassment.

The U.S. Equal Opportunity Commission published the new harassment guidelines Monday after voting along partisan lines on Friday to approve them, even in the face of opposition from nearly two dozen red states. Three Democrat appointees approved the rules while two Republicans opposed them.

The new document elevates gender identity as a protected class under discrimination laws like race, sex and religion.