NEW YORK — More than a month after a liberal advocacy group publicly called on advertisers to boycott Sean Hannity’s show on Fox News Channel, luxury carmaker Cadillac has been the only new company to publicly back away from the program.

While Hannity has appeared largely impervious to the efforts against him, opponents say they’re not giving up.

Meanwhile, Hannity is ascendant at Fox. His show, which averaged nearly 2.7 million viewers in August, was the second most-popular program in cable news behind MSNBC’s Rachel Maddow, according to the Nielsen company. Starting Monday, Hannity moves back to the 9 p.m. Eastern time slot he previously occupied, taking Maddow on directly.

Fox wouldn’t discuss his advertising.

Cadillac pulled its commercials after becoming aware of commentary on Hannity’s program following violence at a rally held by white supremacists in Charlottesville, Virginia.

“In the strongest possible terms, we at Cadillac condemn any form of racism or discrimination,” company spokesman Andrew Lipman said. “We have a zero tolerance policy as it pertains to any of our employees and business partners.”

Media Matters said some dozen advertisers have told the organization they will not purchase commercials on Hannity’s show in the future; some have current contracts and are staying put until those commitments are completed.