A familiar face on the campaign trail, former Cold Stone Creamery CEO Doug Ducey, will not be part of tonight's debate here in Tucson.

A spokesperson for the Ducey campaign said the Republican candidate for governor had a conflict, preventing him from participating in first debate to be held in Tucson.

Another candidate forum here in Tucson, held roughly two weeks ago, only attracted only Republican candidate, Secretary of State Ken Bennett. Former Mesa Mayor Scott Smith did not attend but sent a representative to speak for him.

A representative for the League of Women Voters of Greater Tucson said all the candidates were invited shortly after all six candidates had filed their campaign paperwork. 

Attending tonight's debate will be former GoDaddy Executive Christine Jones, former US Congressman Frank Riggs, former Maricopa County Attorney Andrew Thomas, Smith and Bennett. 

Tickets are still available for tonight's debate,  which starts at 6:30 p.m. at the Proscenium Theatre at the Center for the Arts on the west campus of Pima Community College. They can picked up at the PCC before the debate.

The event will be moderated by Lorraine Rivera, the host of Arizona Public Media’s Arizona Week.

The forum will also be streamed live at AZPM's web site and available for on demand streaming until August 26.

Contact reporter Joe Ferguson at jferguson@tucson.com or 573-4346. Follow him on Twitter @JoeFerguson