The story of Thursday's Republican debate is who won't be showing up: front-runner Donald Trump. The celebrity businessman pulled out of the event amid a spat with Fox News, which is hosting the debate scheduled to take place at the Iowa Events Center in Des Moines. 

Trump pulled out from participating in the event amid an ongoing tiff with Fox News on-air personality Megyn Kelly. "Megyn Kelly’s really biased against me," Trump said in an Instagram video posted earlier in the week. "She knows that. I know that. Everybody knows that. Do you really think that she can be fair at a debate?"

Kelly is scheduled to moderate Thursday's debate along with her colleagues Bret Baier and Chris Wallace. Serving as a moderator in an August debate, Kelly prodded Trump on past comments toward women. After contentious statements from the network and Trump's camp, the GOP frontrunner confirmed Tuesday he would not attend.

As has become the norm for the expansive Republican field, Thursday night will feature an early debate with candidates registering lower support, which will be followed by a primetime debate. The undercard debate is expected to feature businesswoman Carly Fiorina, former Arkansas Gov. Mike Huckabee, former Pennsylvania Sen. Rick Santorum and former Virginia Gov. Jim Gilmore. The main stage is expected to feature Texas Sen. Ted Cruz, Florida Sen. Marco Rubio, retired neurosurgeon Dr. Ben Carson, former Florida Gov. Jeb Bush, New Jersey Gov. Chris Christie, Ohio Gov. John Kasich and Kentucky Sen. Rand Paul. 

Heading into the debate, Trump leads the GOP field nationally with 36.2 percent support, compared with 19.3 percent for second-place Cruz and 11 percent for third-place Rubio, according to the RealClearPolitics average of polls. The debate is the final one scheduled before the Iowa caucus Feb. 1, which has been predicted to be a tight race between Trump and Cruz.

Listed below is the information you need to watch the Republican candidates debate one last time before the Iowa Caucuses:

Main Debate

Start Time: 9 p.m. ET 

TV Channel: Fox News

Online: You can watch a livestream here

Radio: Fox News Radio will play the debate, check for your local channel here. The debate will also broadcast over SiriusXM channel 114.

Early Debate

Start Time: 7 p.m. ET 

TV Channel: Fox News

Online: You can watch a live stream  here

Radio: Fox News Radio is scheduled play the debate, check for your local channel here. The debate is expected to  play on SiriusXM channel 114.