A rule tweak could dramatically shake up the next GOP debate

As few as six candidates could stand on the main stage of the next Republican presidential debate, according to qualification rules released by the network hosting the forum.

Fox Business, which is hosting the January 14 GOP debates in South Carolina, announced a tweak in qualification rules that could limit the candidates on the main stage.

The network will host two debates - an earlier, "undercard" forum for lower-tier candidates, and a later, prime-time debate for the top-tier contenders.

To qualify for the prime-time debate, a candidate must do one of three things:

• Place in the top six nationally, based on an average of the five most recent national polls recognized by Fox News.
• Place in the top five in Iowa, the first-caucus state, based on an average of the five most recent Iowa state polls recognized by Fox News.
• Place in the top five in New Hampshire, the first-primary state, based on an average of the five most recent New Hampshire state polls recognized by Fox News.

To qualify for the lower-tier debate, candidates must register at least 1% support in one of the five most-recent national polls. The network will factor in polls conducted and released prior to January 11 at 6 p.m. ET.

According to the Real Clear Politics average of national polls and surveys in Iowa and New Hampshire, just six GOP candidates would currently qualify for the prime-time event: real-estate tycoon Donald Trump, Sen. Ted Cruz (R-Texas), Sen. Marco Rubio (R-Florida), retired neurosurgeon Ben Carson, former Florida Gov. Jeb Bush (R), and New Jersey Gov. Chris Christie (R).

Other contenders, such as Sen. Rand Paul (R-Kentucky), former Hewlett-Packard CEO Carly Fiorina, and Ohio Gov. John Kasich (R) would be relegated to the "undercard" affair.

Fox Business also hosted a November GOP debate series, which earned the network record ratings of 13.5 million viewers.