The City Council, which passed the first ordinance allowing for more than one domestic partner, approves a new policy to prevent discrimination.

Somerville secured its place as a supportive hub for people in polyamorous relationships Thursday night when the City Council unanimously approved an antidiscrimination ordinance to protect people in polyamorous and other consensually nonmonogamous relationships.

The ordinance — the first of its kind, according to those involved — prohibits employment and policing discrimination against those in relationships of two or more people.