When is the first presidential debate with Donald Trump and Hillary Clinton, and how can you watch it?

Who will gain the upper hand in the first of three televised presidential debates?

The first of three presidential debates between the Democratic and Republican contenders for the White House will be held on Monday 26 September.

It will be the first time that Donald Trump and Hillary Clinton have gone head to head in what has already proved a bitter and divisive general election campaign.

Ms Clinton has seen her national lead in the polls eaten away by the bombastic property mogul. He has even begun eking out an advantage in some of the crucial swing states.

Monday evening’s clash will be the first chance to see how Ms Clinton’s cool, considered style of debate - heavy on references to experience - deals with Mr Trump’s bluster and hyperbole.

Here’s everything you need to know before the big event.

When and where is it?

The first debate is being held at Hofstra University on Long Island, New York. It is the third time it has played host - a record. The debate is due to start at 9pm local time and will finish at 10.30pm.

Who will be hosting it?

NBC will host and broadcast the first debate. Lester Holt, a Nightly News anchor, will be the night’s moderator, asking the questions.

Lester Holt with his colleague Andrea Mitchell during a Democratic presidential debate in January (Reuters)

How does it work?

The nonpartisan Commission on Presidential Debates has responsibility for overseeing the event and ensuring fair play. The debate is divided into six segments of 15 minutes. Each segment starts with question from the moderator with the candidates afforded two minutes to answer, before responding to each other followed by what the CPD describes as “a deeper discussion of the topic”.

Mr Trump and Ms Clinton will face off alone, after the commission decided that third party candidates Gary Johnson and Jill Stein had not amassed enough support to qualify.

What topics will be discussed?

The subjects for each of the three debates are being announced one week in advance. The first is to cover “America's Direction”, “Achieving Prosperity”, and ”Securing America”.

How can I watch it?

The TV networks have agreed to show all the debates, so they will be available on C-SPAN, Fox, ABC, NBC, CBS, CNN, and MSNBC. Several are promising to livestream the event online too. There will no commercial breaks during any of the debates.