Minneapolis Mayor Jacob Frey has joined 160 other mayors across the country in urging U.S. Secretary of Commerce Wilbur Ross to reject the Department of Justice's request to add a citizenship question to the 2020 census.

Frey signed a letter from the U.S. Conference of Mayors arguing that asking people about their citizenship status would deter people living in the country illegally from participating in the census, invade people's privacy and be difficult to implement. The mayors wrote that it would threaten the Census Bureau's ability to "conduct an inclusive enumeration that accurately reflects the diverse fabric of America."

The mayors also asked Ross to pursue more funding to carry out the census and appoint a qualified Census Bureau director.

"Mayors across the country are a united front for a fair census that accurately represents our country," Frey said in a statement. "Ensuring that our immigrant and New American communities can participate in the census without intimidation is the right thing to do and crucial for the fair representation of diverse cities like Minneapolis."

The letter is a response to a December request from the Justice Department to interim Census Bureau director Ron Jarmin arguing that a count of voting-age citizens is critical to enforcement of the Voting Rights Act and its protections against racial discrimination in voting.

"To fully enforce those requirements, the Department needs a reliable calculation of the citizen voting-age population in localities where voting rights violations are alleged or suspected," the letter said.

The census last included a question about citizenship in 1950.

The pushback against a citizenship question is coming not just from mayors. Nineteen state attorneys general sent a similar letter to Ross, calling such a question "unconstitutional."

Duluth Mayor Emily Larson is among the signatories of the Conference of Mayors letter. St. Paul Mayor Melvin Carter is not.