Republican presidential hopeful Mitt Romney told social conservatives Saturday “poisonous language has never advanced our cause” as both he and rival Rick Perry grappled with a flare-up over religion.

Romney, in remarks to the Values Voters Summit, a gathering of cultural conservatives in Washington, did not directly confront the words of a prominent Perry supporter who called Romney’s Mormon faith a “cult.” Indeed, he was criticizing another speaker at the meeting who is known for anti-Mormon and anti-Muslim rhetoric, and who followed him on stage.

But his cautionary words served as notice that attacks on faiths should, in his view, be off the table. He appealed to the social conservatives to support a presidential candidate who has the best record on the economy.

Perry planned a day of campaigning in religiously conservative northwest Iowa. On Friday, the Texas governor answered simply “no” when asked if he thought Mormonism was a cult. But that did not appear likely to be the last word on the subject.

Earlier in the day, Dallas pastor Robert Jeffress branded Mormonism a cult and said Romney is “a good moral person, but he’s not a Christian,” in remarks introducing Perry to a crowd. Perry accepted the introduction by saying Jeffress “hit it out of the park…”