SALT LAKE CITY — A rival church elder is fighting to keep jailed polygamous sect leader Warren Jeffs in charge of his Utah-based church after another member seized the presidency this week.

In papers filed with the Utah Department of Commerce on Thursday, Boyd L. Knudson claims that William E. Jessop never had authority to assume the role as president of the corporation that is the Fundamentalist LDS Church.

"I declare that according to church rules, William Edson Jessop has never been upheld by the church congregation as president of the Fundamentalist Church of Jesus Christ of Latter Day Saints. Common consent is required by the church," Knudson wrote in an affidavit.

Knudson is the church's registered agent. Four other people considered Jeffs loyalists, including his brother Lyle Jeffs, also filed affidavits with the department in support of Jeffs' presidency.

Jessop, 41, took over the church Monday after filing papers with the department. Knudson now seeks to reinstate Jeffs as president, which sets up a potential legal battle as the two vie for control.

Jeffs, 55, remains jailed in Texas while awaiting trial on bigamy and sexual assault charges.

Commerce spokeswoman Jennifer Bolton said Tuesday that if Jeffs mounted a challenge to Jessop, the department's Division of Corporations would place a "hold" on Jessop's papers and grant both sides up to 30 days to prove their right to the presidency.

If it can't be resolved, the state will ask the courts to settle the matter. A legal loss for Jessop would mean the church's presidency reverts back to Jeffs.

Rod Parker, an attorney who represents the FLDS church in civil matters, declined to comment Thursday.

In 2007, while in a southern Utah jail, Jeffs seemingly ceded the presidency of the 10,000-member church to Jessop.

"I know of your ordination, that you are the key holder, and I have sent a note with my signature so that there is no question," Jeffs told Jessop in the Jan. 24, 2007, telephone call. A recording of that call and others were released by the Utah courts.

In other calls at the time, Jeffs told family members and other church leaders that the presidency belonged to Jessop.

Jessop did not respond to the offer at the time, and Jeffs publicly remained spiritual head and president of the church. Some church members speculated the calls from Jeffs were merely a test of their faith.

Four days later, Jeffs attempted suicide by trying to hang himself in jail.

Then in December 2007, after his Utah conviction on two felony counts of rape as an accomplice, Jeffs resigned as president of the church corporation, believing he could no longer run its day-to-day business from behind bars, but he remained the group's spiritual leader.

His Utah convictions were later overturned, and he was transferred to face charges in Texas. Last month, however, he retook control of the church following the abrupt resignation of his replacement, who was forced out.

Jessop says he is only stepping forward now because he believes he can help provide the church with the leadership it needs while Jeffs is incarcerated.

Jeffs assumed the role as FLDS prophet and president in September 2002 following the death of his father, Rulon Jeffs, who suffered a series of strokes.

His rise to power has been questioned by former church members who say there was no succession plan in place when the elder Jeffs died. They say Rulon Jeffs had preached that the second coming of Jesus Christ was imminent, and therefore no one would need to lead the church in the future.

The FLDS practices polygamy in marriages arranged through church leaders. Historically some unions have involved underage girls. But after a raid on the church's Eldorado, Texas, ranch in 2008, a church spokesman said the faith had halted the practice.