A Southern California city just threw down the gauntlet against Gov. Gavin Newsom’s immigration policy.

Huntington Beach, a city of around 200,000 in Orange County, passed a “non-sanctuary city” resolution that instructs law enforcement to cooperate with Immigration and Customs Enforcement and other federal agencies as they ramp up their fight against migrant crime.

The declaration takes aim at a 2017 law, championed by Newsom, that forbids state and local resources from aiding federal immigration authorities.

Under that law, local law enforcement could not detain someone for being in the country illegally, or assist organizations like ICE in identifying and apprehending undocumented immigrants.

“It’s a basic public safety issue … If someone has already been arrested for a crime, and we find out they are undocumented, we still have to let them go. And now they’re out in the community,” Casey McKeon, one of the city council members who unanimously supported the resolution, told The Post.

Huntington Beach officials claimed the law hamstrung their law enforcement’s ability to protect the city, citing state records that show a 20% upswing in violent crime since the sanctuary law — SB 54, aka the “California Values Act” — went into effect.