"It'll be chaos if the interveners are allowed to come in," said Jeff Shields, who represents trust fiduciary Bruce Wisan.
The state in 2005 took over the trust, which controls virtually all the property in the primarily FLDS towns of Hildale and Colorado City, located on the Utah-Arizona border, and in Bountiful, British Columbia, after allegations of mismanagement.
The FLDS church initially did not participate in the UEP case, but in 2008 stepped up to protest the sale of Berry Knoll Farm, calling it the community's bread basket and a future temple site. The original motion to intervene was filed then by three men who were using the land. Added later were Short Creek Bishop Lyle Jeffs, brother of FLDS prophet Warren S. Jeffs, and James Oler, bishop in the sect's Canadian settlement.
No acting member of the sect has been a party to the proceedings. But on Nov. 16, 3rd District Judge Denise Lindberg allowed FLDS President Wendell Nielsen to intervene in future trust proceedings.
The state, which is also charged with watching out for the good of the church members, says Nielsen's voice is enough and that additional sect members would further complicate an already tangled case.
With that in mind, Supreme Court Justice Thomas Lee asked whether the problem might still be resolved in the lower court.
"Shouldn't we dismiss the appeal ... because it's not ripe?" he asked.
FLDS attorney Stephen Clark argued the conditions placed on Nielsen in order for him to participate such as disclosing all records relating to the trust were too limiting.
He said Nielsen is solely a religious leader, and the members of the sect also need representation from people who also have secular responsibilities, such as the bishops.
If the appeal is successful, FLDS attorney Rod Parker said the bishops would seek to tackle what they see as problems with the administration of the trust, including the still-pending sale of the farm.
Church members "have a right to due process, a right to be heard," Parker said.
But Utah Assistant Attorney General Tim Bodily said that if the justices side with the FLDS, little would change.
"They'll be more litigation, more attorney filings, but I don't think it will change the outcome," he said.
The justices will issue their ruling in the case at a later date.