DENVER — The United States Department of Justice (DOJ) has launched its first official legal action against the City of Denver and the State of Colorado, challenging so-called “sanctuary policies.”

The Trump administration has asked a judge to overturn state and city policies restricting local cooperation with federal immigration officials. The lawsuit filed Friday lists Democratic Gov. Jared Polis, Mayor Mike Johnston, Democratic Attorney General Phil Weiser and Sheriff Elias Diggins as defendants.

The lawsuit accuses the state and local leaders of improperly preempting the federal government’s ability to carry out immigration enforcement. It challenges the constitutionality of several state laws limiting local law enforcement’s ability to enforce immigration law and share information with U.S. Immigration and Customs Enforcement (ICE) and restricting ICE’s ability to enter jails or interview inmates they suspect of violating immigration laws.

The lawsuit also seeks to overturn a Denver ordinance that prohibits city employees from using city resources to assist federal immigration officers and bars ICE from entering secure areas of city jails without a warrant signed by a judge.

The DOJ argues those policies are too restrictive and require ICE agents to “engage in difficult and dangerous efforts” when they attempt to detain people outside of jails.

The lawsuit also claims the state laws impede the ability of Republican-led counties like Douglas County from willingly working with ICE.

In March, Mayor Johnston was one of four mayors to testify before Congress as House Republicans investigated “sanctuary cities.” Johnston claimed in an interview with The Denver Gazette’s news partners, 9NEWS, after he testified that the city does work with ICE within the confines of federal and state laws.

“We don’t ask someone’s status when we arrest them or when they come to a library, but we do collaborate with ICE to pursue violent criminals,” Johnston said. “We do that now, and if we have someone in our custody, they send us a detainer request, and what we do is we notify them when they’re going to be released.”

In a statement to 9NEWS, the mayor’s office said, “Denver will not be bullied or blackmailed, least of all by an administration that has little regard for the law and even less for the truth. Denver follows all laws local, state, and federal and stands ready to defend its values.”

Attorney General Weiser has already filed 15 lawsuits against the Trump administration. In a statement to The Denver Gazette’s news partners, 9NEWS, responding to the DOJ’s lawsuit, the attorney general’s office said it “is committed to defending Colorado law and has done so successfully in the past in this area. We stand ready to do so again.”

A spokesperson from the governor’s office provided the following statement:

“Colorado is not a sanctuary state. The State of Colorado works with local, state and federal law enforcement regularly and we value our partnerships with local, county and federal law enforcement agencies to make Colorado safer. If the courts say that any Colorado law is not valid then we will follow the ruling. We are not going to comment on the merits of the lawsuit.”

The DOJ has filed similar lawsuits against immigration policies in Rochester, New York, the City of Chicago and the State of Illinois.

For more on this story and other Denver news, visit our news partners at 9NEWS.com.