Two powerful California tribes have publicly expressed their concern over state regulators’ efforts to approve daily fantasy sports legislation.

On Wednesday, the Sacramento Bee reported that the leaders of two influential California tribes – the Morongo Band and San Manuel Band of Mission Indians – had written letters to state Assemblyman Adam Gray expressing their concern over the speed with which Gray’s DFS bill is proceeding through the legislature.

Gray is the author of AB 1437, which seeks to regulate, license and tax DFS activity in the state. The Assembly approved the bill by a margin of 62-1 last month, with only Assemblyman Marc Levine expressing opposition. Levine has called on state Attorney General Kamala Harris to offer her opinion on the legality of DFS, but Harris has so far kept her cards close to her chest.

Morongo chairman Robert Martin’s letter to Gray echoed Levine’s doubts over the legality of DFS. Martin said the members of his tribe were “very concerned that a retroactive approval of a form of gaming that is otherwise illegal, simply because it is popular, is a very dangerous precedent.”