The city of South Miami is preparing to fight a controversial new law aimed at banning so-called sanctuary cities, after commissioners unanimously agreed to hire an attorney to handle the legal challenge.

The ban, signed into law by Gov. Ron DeSantis last month, was one of the most fiercely fought issues of the 2019 legislative session that ended in May. The measure came after DeSantis vowed during his 2018 campaign to prevent sanctuary cities.

The law is designed to spur local law-enforcement agencies to fully comply with federal immigration detainers and share information with federal immigration authorities after undocumented immigrants are in custody. Under the new law, local governments are required to “use their best efforts to support the enforcement of federal immigration law.”

But during a brief special meeting Tuesday evening, South Miami Mayor Philip Stoddard echoed critics' concerns that the law would discourage undocumented residents from reporting crimes.

“Our police are responsible for maintaining the public safety, and as soon as they are seen as somebody who might turn you in if you called for assistance, they're no longer trusted and they can no longer do their primary job of keeping all the citizens and all the residents of a community safe,” Stoddard said. “It creates divisions.”

Stoddard, who said the city had been approached about the lawsuit by the Southern Poverty Law Center, said the statute is vague and overrides local authority.

“This state-level anti-sanctuary movement not only looks to repeal local sanctuary policies, it is also aimed at eliminating the discretion that local communities have traditionally exercised over their involvement in federal immigration enforcement efforts,” the resolution approved by the city commission states.

City Attorney Thomas Pepe warned the commission that several economic issues could arise from complying with the law, such as a lack of reimbursement from federal agencies and potential lawsuits against the city.

“If the city detains someone and there is no warrant, and nine times out of 10 there is no warrant other than an administrative warrant, the city could be liable for a due-process, equal-protection kind of claim that could be filed by the person that was detained by the city,” Pepe said.

When signing the bill into law in June, DeSantis said the measure will help ensure the safety of communities.

“This is about the rule of law,” he said at the time. “It's also about public safety.”

But opponents blasted the governor for signing the measure, which was sponsored by Sen. Joe Gruters, a Sarasota Republican who doubles as chairman of the Republican Party of Florida, and Rep. Cord Byrd, R-Neptune Beach. Critics of the proposal have argued, in part, that the law will lead to increased detention and deportation of undocumented immigrants, including people stopped by police for minor offenses.

An arm of the Southern Poverty Law Center previously issued a statement alleging that the measure violates the U.S. Constitution's Fourth Amendment ban on unreasonable seizure.

“The legislation signed by Governor DeSantis today is unconstitutional, and Republican lawmakers knew this when they fast-tracked the bill to appease anti-immigrant voters and use racial grievance to drive a wedge between Floridians,” Scott McCoy, senior policy counsel for the SPLC Action Fund, said after the governor signed the measure. “This law forces local and state police to detain people for federal immigration authorities without probable cause.”

Jim Turner reports for the News Service of Florida.