SALT LAKE CITY?Organizers of a petition drive to hike taxes on radioactive waste disposal asked the Utah Supreme Court to throw out a portion of the statute that invalidated more than 91,000 signatures for the November ballot initiative.

Six initiative sponsors and activists filed a petition of extraordinary writ with the state Supreme Court on Tuesday.

The signatures for the Radioactive Waste Restrictions Act were subject to Lt. Gov. Olene Walker’s validation. Her office declared the petition invalid after organizers failed to get signatures for 10 percent of the registered voters in 20 of Utah’s 29 counties.