WASHINGTON — Thomas Perez, an assistant US attorney general for civil rights who is a first-generation Dominican American, is President Obama’s choice to be the next labor secretary, according to two people in the administration familiar with the decision.

Perez, 51, has strong labor support and served as labor secretary for Maryland Governor Martin O’Malley, a Democrat, from 2007 until 2009, when he was picked for the Justice Department position. Perez also served on the Montgomery County Council in Maryland and was the first Latino elected to the council. He has been the key official under Attorney General Eric Holder Jr. handling civil rights cases.


Reached by telephone Saturday, Perez said: ‘‘I can’t really discuss it, I apologize.’’ White House officials also declined to comment.

Perez would replace Hilda Solis, who resigned in January. If nominated and confirmed, he would satisfy requests from Latino groups for representation in Obama’s second-term Cabinet.

But Perez’s possible nomination, which must be confirmed by the Senate, was already drawing criticism from one Republican lawmaker, Senator Charles Grassley of Iowa. In a statement, Grassley said that if Perez is nominated, ‘‘he should face a lot of tough questions’’ about the Justice Department’s role in a decision last year by St. Paul, Minn., to withdraw a housing discrimination case that was before the Supreme Court.

On civil rights, Perez’s division oversaw voting rights cases against South Carolina and Texas. The Justice Department blocked a Texas law last year that required voters to show a photo ID, following similar action in 2011 to block a voter ID law in South Carolina.