An ad blitz promoting a transportation tax referendum is largely supported by local companies, according to records obtained by Channel 2 political reporter Lori Geary.

The “Untie Atlanta” ad campaign has swept across metro Atlanta television and radio stations in recent months in anticipation of the July 31 statewide primary.

Voters are being asked to approve a one percent sales tax increase that would raise $8 billion for transportation and transit projects in 10 metro counties. Other areas of Georgia are voting on their own regional tax and project list.

Dave Stockert, chairman of Citizens for Transportation Mobility, told Geary the multi-million dollar campaign has been largely contributed by companies in the metro area.

"Corporations are the ones that can do it.  It's not about taking the bread off the table for a family, everybody pays for congestion already," Stockert said.

Documents show Stockert’s group has raised $6.5 million so far, including $250,000 each from the Georgia Association of Realtors, Georgia Highway Contractors Association, Georgia Power, The Coca-Cola Company, Yancey Brothers and Cox Enterprises, the parent company of WSB-TV.  Clear Channel donated $300,000 in billboard space.

Opponents of the sales tax claim big business and contractor who stand to gain from the road and transit projects are pumping money into the campaign.

“They’re trying to buy this election,” said state Sen. Vincent Fort.

Stockert told Geary about 20 percent of the money raised came from contractors who would benefit directly from the projects, but he disagrees about their motives.

“They’ve been decimated along with the rest of the construction business in this region with the financial downturn. They’d like to put people back to work,” Stockert said.

Click here to see the list of donations made to Citizens for Transportation Mobility Inc.