ATLANTA (AP) - Is there a difference between raising taxes and supporting a ballot measure that would raise taxes?

Georgia tea party activists say no. And they are vowing to stir up trouble for state officials who campaign for a regional transportation tax before voters in November - especially those who signed a pledge promising to oppose any efforts to increase taxes.

The split among Republicans could mean some sitting lawmakers will face a primary challenger, with tea party activists saying they will field candidates to oppose those who support the transportation tax. The activists say any official who campaigns for the transportation measure, including Gov. Nathan Deal, is violating his pledge not to raise taxes.

"There is no middle ground," said Debbie Dooley, national coordinator for the Tea Party Patriots. "Voters really don't have a lot of patience with elected officials who break their promises from the campaign trail, and they will hold them accountable when they're up for re-election."

Fayette County Commissioner Steve Brown, who works with the Fayette County Issues Tea Party, said the county has been one of the most vocal opponents in the state on this issue. He put the consequences more plainly.

"Everybody who supported it has lost re-election in our county," Brown said. "If you go that way, you will not be in office very long."

Every member of the Legislature is up for re-election this fall, including House Speaker David Ralston.

The transportation tax plan, which passed overwhelmingly in the Legislature and was signed into law in June 2010, divides the state into groups. A regional roundtable has approved a $6.14 billion list of local transportation projects, and voters must decide whether to hike their sales tax by 1 cent to fund those projects.

Those who oppose the referendum say it would be the largest tax hike in state history and could become an unfair burden that favors some communities over others. But Deal, Atlanta Mayor Kasim Reed, and House and Senate leaders have backed the measure, and the governor and mayor say its passage is crucial to the economic prosperity of the region.

The governor, 14 senators and 40 representatives have signed the Taxpayer Protection Pledge authored by Grover Norquist, president of Americans for Tax Reform, a group that advocates against tax hikes.

Earlier this month, a letter addressed to Deal and signed by tea party activists from around the state raised concerns about Republican leaders' support for the transportation tax.

"The hard-working base that made every primary election vote count needs the leadership we were promised," the letter reads. "Thus far, we have found little to cheer about with the (transportation tax) and the elected officials who support it."

Deal spokesman Brian Robinson said in a statement that Deal has kept his pledge to oppose tax increases, and that the referendum was passed before Deal was elected.

"The referendum adheres to the ideals that the Tea Party expresses: Giving voice to citizens and treating them all equally," Robinson said. "Those who want the referendum off the ballot need to explain why they want to silence the voice of voters."

House Speaker David Ralston has signaled that while he supports the transportation referendum, he will not try to persuade citizens to vote one way or the other. Lt. Gov. Casey Cagle, who is not up for re-election this year, said he has not decided if he will campaign on the issue.

Senate President Pro Tempore Tommie Williams, who voted in favor of the referendum two years ago, said there is a need to address transportation congestion in the state and find additional ways to fund road projects. He said the decision to let voters weigh in is a fair one.

"If I had just raised taxes without asking the people to vote, that'd be one issue," Williams said. "That's not what we did. We gave the people of Georgia the opportunity to determine for themselves if they think that need is valid, based on a project list. If they like that project list, they should support it."

Williams said the issue will not affect his re-election campaign this fall, and that he doesn't have a problem with tea party activists challenging those who would campaign in favor of the transportation tax.

"They're an interested group of taxpayers, and I'm happy they're there," he said. "They hold people accountable."