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

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

Front-runner Donald Trump will appear at center stage, flanked by retired neurosurgeon Ben Carson and Sen. Ted Cruz, who is surging in Iowa, leading second-place Trump by 10 percentage points in the Des Moines Register/Bloomberg Politics poll released Saturday night. Other GOP hopefuls who qualified for the main stage include Florida Sen. Marco Rubio, 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 with contests on the road to the nomination.

The network says lower-polling GOP hopefuls will debate earlier Tuesday night. They are former Arkansas Gov. Mike Huckabee, former Pennsylvania Sen. Rick Santorum, South Carolina Sen. Lindsey Graham and former New York Gov. George Pataki.

Associated Press