Republican Debate
Republican U.S. presidential candidate and businessman Donald Trump (center) speaks as U.S. Sen. Marco Rubio (left) and Dr. Ben Carson listen during the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates, in Milwaukee on Nov. 10, 2015. Reuters/Jim Young

It has been over a month since the last Republican presidential debate and this time around the candidates will be sparring in Las Vegas at the Venetian hotel. Gloves have come off in recent days with businessman front-runner Donald Trump going after Texas Sen. Ted Cruz, who has risen in the polls.

Trump will be center stage during the prime-time debate flanked by eight other candidates: retired neurosurgeon Ben Carson, Cruz, Florida Sen. Marco Rubio, former Florida Gov. Jeb Bush, former Hewlett-Packard CEO Carly Fiorina, New Jersey Gov. Chris Christie, Ohio Gov. John Kasich and Kentucky Sen. Rand Paul. Only four candidates will be on stage for the early debate, CNN reported. Those candidates with low polling numbers are Arkansas Gov. Mike Huckabee, former Pennsylvania Sen. Rick Santorum, South Carolina Sen. Lindsey Graham and former New York Gov. George Pataki.

During a rally in Kentucky earlier in the month, Trump had threatened not to participate in the debate, requesting that CNN donate $5 million to support wounded veterans. Trump said CNN “doesn’t treat me properly.” The network declined to make any payment to have Trump appear in the debate.

The debate comes after Trump made controversial remarks about banning the immigration of Muslims to the U.S. A majority of Americans do not support Trump’s proposed ban.

This will be the last Republican debate of 2015 as the candidates focus on the Iowa caucus Feb. 1. Here is everything you need to know to watch the debates Tuesday:

Main Debate

Start time: 8:30 p.m. EST

TV channel: CNN

Online: CNN is offering live-stream coverage of both debates from 5 to 11 p.m. EST on its home page and on mobile devices.

Radio: Salem Radio is co-hosting the debate with CNN. Find your local station here to listen live.

Early Debate

Start time: 6:00 p.m. EST

TV channel: CNN

Online: CNN.com

Radio: Listen live from your local affiliate or nationally with CRN Digital Talk Radio.