Merchants at Los Angeles’s Olvera Street are seeking to join a legal case over a cross erected in 1929 and an annual Nativity display, arguing that removing them would damage traditions tied to the area’s Mexican-American Catholic heritage. Their lawyer, Andrea Butler of the religious-liberty group Becket, said the dispute could set a broader precedent affecting religious monuments and cultural celebrations elsewhere in the United States.

A resident sued the city last year, seeking the removal or covering of the cross and an end to the December Nativity display, saying they felt excluded as a non-believer. Becket filed with the Ninth Circuit on Monday to allow the Olvera Street Merchants Association Foundation to participate; it says many merchants are from third- and fourth-generation families connected to the market, which opened in 1930 and forms part of the El Pueblo historic district visited by millions each year.