Several weeks after Denver’s mayor said immigrants here were denied American citizenship because of their work in the cannabis industry, President Donald Trump’s administration issued a formal policy making clear that is occurring and will continue to occur.

U.S. Citizenship and Immigration Services published a one-page policy Friday stating that “violation of federal controlled substance law, including for marijuana, remains a conditional bar to establishing good moral character for naturalization, even where that conduct would not be an offense under state law.”

The policy codifies what Mayor Michael Hancock and immigration attorneys have said is occurring: Legal immigrants in Colorado seeking American citizenship are being found to have poor moral character because they work with marijuana, which is prohibited under federal law.

“An applicant who is involved in certain marijuana related activities may lack good moral character if found to have violated federal law, even if such activity is not unlawful under applicable state or foreign laws,” Citizenship and Immigration Services wrote.

That has frustrated Colorado politicians on the left and right. On April 3, Hancock and Denver’s city attorney called on the Trump administration to reconsider the policy, saying it has harmed two Denver area immigrants who have lived here for decades and are upstanding citizens.

One of them is Oswaldo Barrientos, who came to the United States when he was 1 year old, has no criminal history and has been gainfully employed in the marijuana industry for five years.

“I thought I was a shoo-in” for naturalization, he told the Denver Post earlier this month. “Then I received a letter from the government saying that I ‘lacked moral character.’ I was shocked.”

Bryce Downer, an immigration attorney at Novo Legal who is representing Barrientos, said Monday he believes the new CIS policy is a direct response to the cases Hancock highlighted.

Novo Legal will challenge the policy in federal court, he said. In the meantime, it is advising citizenship applicants who work with marijuana to not waste their $725 filing fee by applying.

“We would advise everyone to sit tight until this gets resolved in the courts,” Downer said.

Sen. Cory Gardner, a Yuma Republican, mentioned the case of Barrientos and others during a press conference in Washington on April 4. Gardner has reintroduced legislation that would prohibit enforcement of the federal marijuana ban in states where it has been legalized.

“We know, today, of news in Denver, where legal immigrants – legal immigrants – are being denied citizenship because of their work. This has to stop,” Gardner said at the time.

Groups that are opposed to marijuana legalization have called for more federal enforcement of the ban on marijuana, including Drug Enforcement Administration crackdowns. Smart Approaches to Marijuana has said many Coloradans are “deeply embarrassed” by Gardner’s bill.