Austin City Council members voted today to challenge the state’s so-called sanctuary city law in court. The council passed a resolution, 10-1, instructing the city manager to “pursue effective litigation and defense” for a legal battle against Senate Bill 4, which was signed into law last week by Gov. Greg Abbott.

Council Member Ellen Troxclair was the sole opponent.

“When my colleagues and I took our oath of office to serve on the Austin City Council, we vowed to ‘protect, preserve, and defend the constitution of the United States.’ That includes fighting unconstitutional mandates by Governor Greg Abbott himself," Council Member Greg Casar said after the vote. "I hope that our vote today inspires more cities and counties across the Lone Star State to draw a line in the sand and defend the rights of all of our community members.”

Abbott and other state lawmakers cited Travis County Sheriff Sally Hernandez’s detainer policy in the lead up to the bill’s passage, with the governor even going so far as rescinding state funding from the county because of it. The current policy honors requests from Immigration and Customs Enforcement agents to detain a person only in cases of suspected murder, human trafficking or aggravated sexual assault.

The law, which goes into effect Sept. 1, requires city and county law enforcement to comply with all requests from ICE to hold people suspected of being in the country illegally. It also allows law enforcement to ask a person’s immigration status during arrest or detainment, and punishes elected officials and law enforcement officials for noncompliance.

Travis County District Attorney Margaret Moore said Thursday that prosecutors will begin giving out letters to some undocumented witnesses and victims that could potentially shield them from deportation.

“The idea is that if they are picked up by law enforcement to be turned over to ICE, they would be able to present this letter," she told KUT's Trey Shaar, "and the request in the letter is for the law enforcement person to verify, to call us and let us know they have that person, so we can take appropriate steps.”

"We want victims and witnesses to feel comfortable coming forward, so maybe this will help with that," she said.

Austin and Travis County officials were vocal in opposing the law during deliberations at the Capitol. Council Member Greg Casar and others were arrested during a sit-in protest earlier this month, and Mayor Steve Adler joined several mayors in Washington, D.C., last month to discern the Department of Justice’s exact definition of a "sanctuary" jurisdiction.

Adler has maintained that both Austin and Travis County are in compliance with federal immigration law and that SB 4 would erode trust between immigrant communities and local law enforcement.

While many predicted legal action from immigrant rights advocates following Abbott’s closed-door signing of the bill, it was the state that sued first.

A day after the signing, Attorney General Ken Paxton asked a federal court to rule on the law, arguing the state was within its 10th Amendment right to enforce immigration. The suit also requested the court streamline all litigation against SB 4 into a single case.

The border town of El Cenizo has also sued the state over the law. San Antonio and Dallas are reportedly planning to discuss taking similar action next week.