Education advocates and members of the faith community on Thursday called on public supporters to join the fight to increase education funding by gathering signatures for a ballot initiative to raise income taxes on the wealthy.

At a news conference outside the Arizona State Building in downtown Tucson, backers of the Invest In Arizona initiative said they were hoping to capitalize on the success of the #RedForEd movement to push their initiative, which would raise an estimated $690 million for education by nearly doubling the income tax rate for people earning more than $250,000 or couples earning more than $500,000 annually.

The initiative, which is fronted by former Democratic Sen. David Lujan of Phoenix, does not have the official endorsement of Arizona Educators United leaders.

But supporters are hoping to piggyback on the #RedForEd movement’s success to overcome the steep hurdle of collecting more than 150,642 valid signatures from registered Arizona voters before July 5 to qualify for the ballot.

Lujan said volunteers have already gathered more than 10,000 signatures since it was announced on Friday, April 27, showing it has strong bipartisan appeal.

“If you look at the march in Phoenix, and I think down here in Tucson, those who have been participating in #RedForEd, it’s been Republicans, it’s been Democrats, it’s been independents. And those are the same people who have already been signing our petitions,” he said.

But the initiative will likely face strong opposition from business interests in the state, including the well-funded Arizona Chamber of Commerce and Industry, which has already promised that if the initiative earns a spot on the ballot, “we will oppose it strongly, and we will urge Arizona voters to do the same.”

Lujan said he’s still working to secure commitments to fund the initiative, and estimated it would cost several million dollars to pay for a robust campaign. No major business groups were present at the press conference, nor have any come out in favor of the initiative.

Supporters were undaunted, and the Pima County Interfaith Council pledged to gather more than 55,000 of those signatures in Southern Arizona.

Ernie Galaz, the head cleric at St. Andrew’s Episcopal Church in Nogales and a member of the Southern Arizona Interfaith Council, said as a former school principal, he knows firsthand how the “systematic stripping of resources from our schools has negatively affected teaching and learning in our community.”

“As a man of faith, and a priest in the church, I cannot stand by silently any longer. This is a moral issue,” he said.

Contact reporter Hank Stephenson at hstephenson@tucson.com or 573-4279. On Twitter: @hankdeanlight