When is the Harris-Trump presidential debate and what are the rules?

Tuesday's event will take place in battleground state of Pennsylvania

Former US president and Republican presidential candidate Donald Trump and Vice President and Democratic presidential candidate Kamala Harris. AFP

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Vice President Kamala Harris and her Republican challenger Donald Trump will face off in their first debate on Tuesday, as the race for the White House heats up.

The event will be hosted by ABC in Philadelphia, Pennsylvania, and moderated by David Muir and Linsey Davis. The face-off between Ms Harris and Mr Trump follows a previous presidential debate in June between Mr Trump and President Joe Biden.

Mr Biden's anaemic performance in the debate led to concerns over his age and cognition, and his eventual decision to withdraw from the presidential race.

The format

The debate is expected to take place over 90 minutes, starting at 9pm Eastern Time, with two breaks for advertisements. In a shift from debates in previous years, candidates will not give opening statements.

Instead, they will each have two minutes to respond to a question, with two-minute rebuttals and one minute for follow-ups. At the end of the debate, each candidate will have the opportunity to present a two-minute closing statement.

A coin toss was held virtually on September 3 which determined Mr Trump will offer the last closing statement and Ms Harris will take the right podium position on screen, stage left.

No audience and muted mics

Both campaign teams have agreed the debate will take place without an audience in the studio and with microphones muted unless a candidate is directed to speak. The rules were the same for the previous debate between Mr Biden and Mr Trump – it was the first presidential debate to take place without a studio audience since 1976.

The Harris campaign had called for microphones to be unmuted, as otherwise it would “serve to shield Donald Trump from direct exchanges with the Vice President”. The candidates will also not be able to ask questions of each other.

Organisers are doubtless keen to avoid the pitfalls of the 2020 debates, when Mr Trump frequently talked over and interrupted Mr Biden, who once famously said to his opponent: “Will you shut up, man?”

No notes, no help from staff

The two candidates will not be allowed to bring any written notes with them and will be provided with a pen and paper, as well as a bottle of water. During the two advertising breaks, the candidates will not be allowed to speak to or interact with campaign staff. No topics or questions will be shared in advance with campaigns or candidates.