Washington (CNN) - The lineup for the first Republican presidential debate of the 2012 cycle is all but set, a GOP source told CNN Tuesday.
Thursday's debate in Greenville, South Carolina, sponsored by Fox News and the South Carolina Republican Party, will feature five potential candidates, the source said: Former Minnesota Gov. Tim Pawlenty, former Pennsylvania Sen. Rick Santorum, Texas Rep. Ron Paul, former New Mexico Gov. Gary Johnson and businessman Herman Cain.
To qualify for the debate, participants were required to meet a series of criteria, including paying a $25,000 filing fee to the state GOP in order to be placed on next year's primary ballot.
The deadline for that filing fee is 5 p.m. ET on Tuesday.
The finalized lineup lacks several marquee names, including former Massachusetts Gov. Mitt Romney, who said Monday he will skip the debate, and former House Speaker Newt Gingrich, who originally planned to take part but later decided not to.
The South Carolina Republican Party would not comment on the lineup and said they would announce details of the event on Wednesday.