The bipartisan U.S. House Committee on Oversight and Government Reform sent a letter to Johnston on Monday asking him to testify. Johnston didn't say if he would but criticized Republicans in Congress on immigration.

Congressional leaders are calling upon Denver’s mayor to testify at an oversight hearing for the city’s alleged refusal to cooperate with federal immigration enforcement and U.S.

Colorado is making national headlines this morning. Yesterday, House Republicans in DC invited Denver's mayor to come to Capitol Hill to testify at a hearing about sanctuary cities.

A congressional committee has asked Denver Mayor Mike Johnston to testify in Washington, D.C., next month to defend the city’s policies limiting local police cooperation with federal immigration enforcement.

The mayors of Chicago, Boston, Denver and New York were also asked to hand over all documents and communications related to their cities' sanctuary status, including those between each city, non-governmental organizations and state officials.

Denver Mayor Mike Johnston issued a statement Monday following the announcement of an investigation by the House Oversight and Government Reform Committee into four "sanctuary cities," including Denver.

Boston Mayor Michelle Wu, along with mayors from Denver, New York and Chicago, was called to testify before the U.S. House Oversight and Government Reform Committee regarding sanctuary city policies in a letter Monday morning.