WASHINGTON - CNN is inviting Gov. Christie back to prime time in the next Republican presidential debate.

The New Jersey governor, who had been dropped from the main stage during the last debate, is one of nine Republican presidential candidates to qualify for the network's prime-time event on Tuesday. Also among them: Sen. Rand Paul of Kentucky, who was "on the bubble" of qualifying late last week, the network said.

Front-runner Donald Trump will appear at center stage, flanked by retired neurosurgeon Ben Carson and Sen. Ted Cruz, who is surging in Iowa. Other GOP hopefuls who qualified for the main stage include Sen. Marco Rubio of Florida, former Florida Gov. Jeb Bush, former Hewlett Packard CEO Carly Fiorina, and Ohio Gov. John Kasich.

Qualifying candidates were required to meet one of three criteria in polls conducted between Oct. 29 and Dec. 13 that are recognized by CNN: an average of at least 3.5 percent nationally or at least 4 percent in Iowa or New Hampshire, the first states to with contests toward the Republican nomination.

Sen. Lindsey Graham of South Carolina, former Sen. Rick Santorum of Pennsylvania, former Arkansas Gov. Mike Huckabee, and former New York Gov. George Pataki - all lower-polling candidates - will debate in a forum set to air at 6:30 p.m. Tuesday, two hours before the main event, CNN said on its website.

GOP Debate

When: 8:30 p.m Tuesday. Undercard will be at 6.

Where: Las Vegas


Moderators: Wolf Blitzer, Dana Bash, Hugh Hewitt.

Main debate: Donald Trump, retired neurosurgeon Ben Carson, Texas Sen. Ted Cruz, Florida Sen. Marco Rubio, former Florida Gov. Jeb Bush, former Hewlett Packard CEO Carly Fiorina, New Jersey's Gov. Christie, Ohio Gov. John Kasich, and Kentucky Sen. Rand Paul.

Undercard: former Arkansas Gov. Mike Huckabee, former Pennsylvania Sen. Rick Santorum, South Carolina Sen. Lindsey Graham, and former New York Gov. George Pataki.