Georgia voters heading to the polls will settle primary races in congressional districts across the state.

The two most hotly contested U.S. House campaigns Tuesday are in the new 9th District in north Georgia that covers Gov. Nathan Deal's former political turf and in eastern Georgia's 12th District to choose a Republican challenger for Democratic Rep. John Barrow.

The north Georgia race pits Republican state Rep. Doug Collins of Gainesville against conservative talk-radio host Martha Zoller and retired school principal Roger Fitzpatrick of Cleveland.

East Georgia voters must decide a four-way GOP race in Barrow's district. State Rep. Lee Anderson of Grovetown faces Augusta businessman Rick W. Allen, Augusta lawyer Wright McLeod and Dublin attorney Maria Sheffield.

An Aug. 21 runoff in the race is likely given the crowded field.

Tags: John Barrow, 9th congressional district, 12th Congressional District, Georgia Primary, Doug Collins, Martha Zoller, Rick Allen, Lee Anderson, Wright McLeod, Maria Sheffield, Roger Fitzpatrick, 2012 Georgia primary