SAN DIEGO (CNS) - Elected officials, including Escondido Mayor Sam Abed and San Marcos Mayor Jim Desmond, and a group of residents will urge the San Diego County Board of Supervisors Monday to join the federal government's lawsuit challenging California's sanctuary state law.

The bill, signed by Gov. Jerry Brown in October, limits cooperation between California law enforcement and federal immigration authorities. It prohibits local agencies from holding some immigrants on the basis of federal detainers, asking about immigration status or sharing information with federal authorities not available to the public, among other provisions.

Opponents believe the law obstructs the deportation of criminals by federal authorities.

"The sanctuary state law is not only unconstitutional, but it is a real threat to public safety because it forces local government to harbor and shield violent criminals," former San Diego City Councilman Carl DeMaio said. "It is imperative that San Diego voters contact the five members of the Board of Supervisors before the vote tomorrow (Tuesday) to urge them to sign on to the lawsuit against the sanctuary city law."

The news conference will be held 11 a.m. at the park behind iHeartMedia, 9660 Granite Ridge Drive.

Proponents of the bill, including the ACLU of San Diego and Imperial Counties, believe it makes communities safer and allows local enforcement to focus on their jobs. Supporters say it makes immigrants living in the country illegally more likely to report crimes -- such as domestic violence -- without fear of being detained by federal authorities.

Supervisors Dianne Jacob and Kristin Gasper have both indicated in Fox News interviews they support joining the lawsuit against SB 54.

"This is a politically super-charged issue as you might imagine," Gaspar, a candidate for Congress, told Fox News. "We're talking about hundreds of emails pouring in from all sides. But let us not forget, let's take the emotion out of this. We're talking about following the constitutional laws of our land."

The Board of Supervisors will discuss the issue in closed session Tuesday.

A group of San Diego business, law enforcement, philanthropic, environmental, faith and social justice figures will hold their own news conference Tuesday urging the board not to join the lawsuit. That event is set for 10 a.m. at the San Diego County Administration Center, Waterfront Park, 1600 Pacific Highway.

At 1 p.m. Monday, the group Indivisible San Diego will hold a rally in front of County Supervisor Bill Horn’s Vista office in an effort to convince him to vote against supporting the lawsuit.

The group stated, “We must protect our people and our State values. This is our chance to fight for the underserved and underrepresented; our chance to be on the right side of history. And we must demand that Supervisor Horn do what is morally and objectively right, and vote in a manner that reflects the fabrics of our very diverse communities. Supervisor Horn needs to vote AGAINST joining this useless and bigoted Amicus Brief.”

“Joining the federal lawsuit is an affront to California values and an attack on the safety and well-being of our communities,” the group added. “As residents of this historically diverse region, we value all residents and acknowledge our interdependence. If immigrants are afraid to call the police and report crimes, we are all less safe. If our local law enforcement agencies use our resources to enforce federal immigration laws, our local priorities are jeopardized. If tax-paying workers are deported, our economy suffers and our tax base declines. The time is now for our collective communities to come together and stand for the civil rights of our most vulnerable residents, our undocumented residents. SB 54 is the law of the land and it should be protected and we will be the ones that protect it.”