The story is in several places. Here's an example from the Phoenix Business Journal.
... two former ACC commissioners, Republican William Mundall and Democrat Renz Jennings, as well as Sunrun Inc. and former Tempe mayor Hugh Hallman seek to disqualify three commissioners because they are not seen as impartial in regard to APS or solar issues.
If the complainants succeed, it will leave the Commission crippled, at least with respect to actions involving the APS request for a rate increase.
If the interveners ultimately prevail, it leaves only two commissioners eligible to hear APS matters. The problem is that three commissioners are required to make decisions. There are provisions in the law for handling this, but it still leaves two-fifths of the commission on the sidelines of any action involving the utility. That has repercussions that roll deeply into rate decisions impacting businesses and utilities.
If the commissioners decline either the recusal or to reverse the rate reset rehearing, the petitioners can take the matter to Superior Court, federal court or the Court of Appeals. They have several options to consider when timing is appropriate.