Democratic Debate #4
Bernie Sanders and Hillary Clinton discuss an issue at the third Democratic debate.Reuters

The fourth Democratic debate and second presidential primary debate of 2016, hosted by NBC News from Charleston, South Carolina, will air live on Sunday (17 January) with all three candidates appearing for the two-hour event. Unlike the Republican debates, there will be no undercard event.

Former Secretary of State Hillary Clinton, Vermont Senator Bernie Sanders and former Maryland Governor Martin O'Malley will be participating. Due to O'Malley's dwindling poll numbers, there was concern that he would not be appearing in the only 2016 debate before the Iowa caucus and New Hampshire primary. However, NBC announced on 14 January that O'Malley would in fact be included.

US election 2016: Guide to the Democrat candidatesIBTimes UK

To qualify for the debate, candidates needed to earn 5% in recent national polls or surveys in Iowa, New Hampshire or South Carolina. An NBC News/Wall Street Journal/Marist University poll released this week found that the former governor had 5% support among likely caucus voters in Iowa—behind Clinton (48%) and Sanders (45%).

Despite being included in the debate, O'Malley has failed to make inroads among Democratic voters. The long-shot candidate has blamed the few and poorly publicised debates the Democratic National Committee (DNC) scheduled. Previous Democratic debates have had poor viewership due to non-prime time TV slots.

When and Where

The debate will be held in Charleston, South Carolina on 17 January and will be broadcast from 9pm EST/2am GMT.

NBC News, which will host the debate along with YouTube and the Congressional Black Caucus Institute, has not revealed its format.

How to Watch

NBC News and YouTube will host the first Democratic debate of the New Year, and as is customary, will make it available on a variety of formats. It will air live on NBC News and be streamed live on YouTube.

The next Democratic debate will be broadcast on 11 February from the University of Wisconsin-Milwaukee in Wisconsin. The PBS-hosted event will be moderated by Gwen Ifill and Judy Woodruff and will air after the Iowa caucus and New Hampshire primary.

IBTimes UK will be live blogging the debates beginning at 9pm EST/2am GMT.