French election: Emmanuel Macron and Marine Le Pen to face off in TV debate

France's two presidential candidates will square off in a marathon live TV debate this evening - their last encounter before votes are cast on Sunday.

Polls still give centrist Emmanuel Macron a commanding lead over far-right leader Marine Le Pen, but the face-off could shift the numbers with the rhetoric of the two becoming increasingly sharp in recent days.

The event, scheduled to last two hours and 20 minutes, is regarded as a must-watch in France and as many as 15 million people are expected to tune in at 9pm (8pm UK time).

Voters are being asked to choose between Mr Macron, a Europhile former banker who wants to cut state regulation in the economy whilst balancing workers' rights, and Eurosceptic Marine Le Pen, who wants to ditch the single currency, close France's borders and impose tough restrictions on immigration.

Ms Le Pen has consistently portrayed Mr Macron as a candidate of high finance and of the establishment - he served as an economy minister in the current Socialist government.

In an interview this week, she said: "His programme is very vague, but in reality it is a simple continuation of Francois Hollande's government."

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:: In profile - Emmanuel Macron

That is a potent narrative for many voters who are demanding change in France and Mr Macron will have to work hard to convince people that his party, En Marche!, offers a new kind of politics.

He is likely to focus heavily on the controversial history of Ms Le Pen's National Front party, seeking to portray her as the heir to her father Jean-Marie's racist, anti-Semitic politics.

Mr Macron has warned he won't pull any punches, saying: "I am not going to use cliches or insults.

"I'll use hand-to-hand fighting to demonstrate that her ideas represent false solutions."

The choreography of the debate has been argued over, and Europe, the economy, immigration and French identity are likely to dominate.

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The pair will be seated (apparently at Ms Le Pen's request as she wears heels) and the studio set to a cool temperature to stop them sweating (think Richard Nixon's 1960 US presidential debate).

There will be no audience and after drawing straws Ms Le Pen will speak first and Mr Macron last.

While millions will watch, surveys suggest the vast majority of voters don't think the TV clash will change their choice for president.

However, Marine Le Pen has shown herself adept at landing punches on Mr Macron in previous debates and will likely try to rile him as she has nothing to lose.

If it turns into a slanging match she could have the advantage. But with a big lead over Ms Le Pen, perhaps all Mr Macron needs to do is keep his cool and not obviously lose to his rival.