The leader of the Southern Baptist Convention will endorse Rick Perry onstage at the Values Voter Summit on Friday, a major endorsement for the Texas governor, The Hill has learned.

The backing of Robert Jeffress is a big get because of his stature in the Southern evangelical community. Perry has long enjoyed close ties Christian conservative activists, and Jeffress in particular. Most recently, the two partnered to organize "The Response," a prayer rally in Houston this summer that drew more than 30,000 people.

Jeffress will take some veiled shots at Mitt Romney's Mormon religion and accuse him of shifting positions on some issues when he introduces Perry on Friday afternoon, according to remarks provided to The Hill.

"Once the smoke clears in several months, conservative Christians will have a choice to make," Jeffress plans to say. "Do we want someone who is a conservative out of convenience, or one who is a conservative out of conviction? Do we want a candidate who is a good, moral person, or one who is a born-again follower of Jesus Christ? I believe that in Rick Perry we have a candidate who is a proven leader, a true conservative and a committed follower of Christ."

Despite Perry's longstanding ties with social conservatives, he has struggled somewhat with that group because of his previous support for requiring teenage girls to get a vaccine against a sexually transmitted disease known to cause cervical cancer, as well as his more centrist immigration stances that have angered some on the right.

Perry needs to have a strong performance Friday in order to woo some of the movement's leaders toward his campaign, but Jeffress's endorsement is a good start.

Jeffress is the pastor of a church in Dallas with 10,000 members and has an influential television and radio show. He stirred controversy last year when he called Islam an "evil religion" that promotes pedophilia.