The Associated General Contractors is ramping up efforts to convince the federal government to sue cities in California, Texas and other states that seek to bar contractors who take part in building the Trump administration’s planned Mexican border wall from doing public construction or gaining tax credits.

No firm has yet lost work, but AGC now is enlisting the U.S. Dept. of Homeland Security—which oversees the estimated $25-billion project—to convince the U.S. Justice Dept. to file suit on constitutional grounds. Last year, the trade group asked the DOJ for the litigation and lobbied President Trump directly but has received no response, said spokesman Brian Turmail. AGC has hired a law firm to boost its effort against the “mean-spirited policy,” he said. A DOJ spokesman declined to comment.

Austin is the latest city to link border wall work and city contracts, enacting the action last month in a 10-1 city council vote. The resolution applies to contractors that work on future wall extensions. Municipal officials in California—who last year took the lead in efforts to ban wall contractors—say they are looking out for the best interests of their communities and the state as a whole. San Francisco, Oakland and Berkeley voted last year to bar wall contractors. Berkeley Mayor Jesse Arreguín and three council members said in a memo that the wall will not only “demonize” people of Mexican and Latin American descent, but will also “waste an enormous amount of taxpayer money.”  

Meanwhile, California Assemblyman Phil Ting has filed a bill that would bar companies that do work on the border wall from receiving a myriad of tax credits and breaks. “Companies decide all the time on whether to participate in tax credit programs,” said Ting, who argued he is not trying to penalize companies. “This is merely a disincentive to companies that want to participate in building a wall that is wildly unpopular in California.” According to media reports, cities in  Arizona, New York, Illinois and Rhode Island also have passed bans or are considering them.