CROSS FINGERS - AND HOPE FOR A 'BLACK SWAN' EVENT

Ms Le Pen hopes for a "Black Swan" event similar to the repeated scandals that sunk the campaign of Mr Fillon in order to tilt the election in her favour.

One possibility is a dump of compromising documents on Mr Macron, not unlike what befell US presidential hopeful Hillary Clinton's campaign before the election last year. According to Web analytics firm Trend Micro, his campaign staffers' e-mail accounts have come under constant phishing attacks by the same Russian outfit that went after Mrs Clinton's e-mails.

Mr Macron's cyber-security chief says no hack has been successful, with the campaign taking extraordinary measures to secure its communications. However, 100 per cent security is an illusion.

Anything to show collusion between Mr Macron and the deeply unpopular French President Francois Hollande would be damaging, as would financial ties to Wall Street.

The electoral mood could also shift in the event of a terrorist attack, reported Politico.

While the shooting of a policeman on the Champs Elysees four days before the first round barely influenced voter behaviour, Mr Nicolas Lebourg, a historian specialising in the far right, suggested that a more "unprecedented attack" could "make the French people reconsider their vote".

PERSUADE FAR-LEFT VOTERS TO SIT OUT THE NEXT ROUND

Her claims of being the people's candidate aside, Ms Le Pen has a lot more to gain from abstained votes by left-wingers than Mr Macron.

Only 15 per cent of people who voted for far-left firebrand Jean-Luc Melenchon in the first round plan to back Ms Le Pen. And her hopes of growing that share were doused on Sunday when Mr Melenchon advised his voters to stay clear of her. Consequently, Ms Le Pen is adopting a strategy to get millions of Melenchon supporters to abstain from voting.

Politico reported that she is getting help from the "neither-nor" movement that has opposed both her and Mr Macron for president. Also, the powerful labour unions are split on the candidates: the unions that supported Mr Macron and opposed Ms Le Pen marched separately on May Day, in stark contrast to 2002, when the different labour unions united to oppose Ms Le Pen's father Jean-Marie Le Pen after he made it into the second round of the presidential elections, reported The New York Times.

French physicist Serge Galam - who predicted Mr Donald Trump's victory and argues that a Le Pen victory is more likely than the polls suggest - says the technique can be effective, with Ms Le Pen requiring a turnout rate of 90 per cent of her potential supporters against 70 per cent of Mr Macron's in order to win.

CONVINCE CONSERVATIVES TO STOP WORRYING

Ms Le Pen is working to convince undecided conservatives to back her by using a message similar to the argument made by former president Nicolas Sarkozy during his failed 2012 re-election bid. To do this, she is giving them Mr Sarkozy with a side of nationalism by co-opting his message and emphasising campaign proposals such as arming municipal cops and allowing the police to shoot first at perceived threats.

She also plagiarised parts of a speech by defeated Republican candidate Francois Fillon to attract more conservatives to her cause. Ms Le Pen is set to inherit about 30 per cent of the votes for Mr Fillon versus 41 per cent of the Fillon votes going to Mr Macron. But 30 per cent of Fillon voters remain undecided and she is trying to win them over by addressing their biggest fear about her: the fact that she wants a referendum on French membership of the EU and to revert to the French currency in the event of a "leave" result, reported Politico.

Last week, Ms Le Pen said abandoning the single currency was not her top economic priority and the measure has not featured on her campaign fliers ahead of the second round, reported Reuters. She has also brought on board a man who never fully embraced the idea of a "Frexit", the defeated conservative independent Nicolas Dupont-Aignan, as her potential prime minister.

A FINAL SPRINT WITH A CLEARER MESSAGE

Ms Le Pen campaigned ahead of the election's first round with the offer of a binary choice between "economic patriotism" and unbridled globalisation.

However, while she emerged as the runner-up, her first-round score was several percentage points below what pollsters predicted, leading party experts to conclude that the choice she offered was too abstract. Some missed the precise meaning of globalisation and misunderstood "economic patriotism" as meaning that Ms Le Pen wanted to roll back checks and balances in the French republic, reported Politico.

Now, in the second round, Ms Le Pen has offered a much simpler message as the candidate who will protect the French.

At a rally in Villepinte near Paris, on Sunday, Ms Le Pen vowed to be the "president who protects" French citizens, particularly women, but also the environment, national borders and "the solidarity that exists among all French people". She also targeted Mr Macron as "the candidate of finance".

"We needed something that got to everyone," said Mr Dutheil de la Rochere. "She has to talk to the left and the right at the same time. But she can't ask left-wingers to switch off the TV while she talks to the right, so we came up with protection."

BET ON MORE MACRON MISTAKES, WIN LIVE TV DEBATE

Ms Le Pen is hoping for easy wins in the final days of the campaign after neophyte campaigner Macron made some mistakes at the start of his second-round campaign.

Mr Macron had delivered a tonally challenged speech after securing the most votes in the first round, then sped off to a celebrity-packed dinner, which gave off an air of celebrating the presidency too early, reported US news website Politico.

He later fell into a Le Pen trap at a Whirlpool factory that was set for closure. While she snapped smiling selfies with workers in the parking lot, he was jeered during tense exchanges with officials by the exit.

While operations to derail the Macron campaign on the ground are ongoing, senior aides to Ms Le Pen say the live debate between the two leaders will be the big showdown. The rivals will try to inflict knockout blows in the debate, with Ms Le Pen going after Mr Macron as a ruthless capitalist bent on exploiting workers, while he will seek to remind French voters that Ms Le Pen's party counts Holocaust revisionists among its senior members and traces its roots back to Vichy France and French Algeria champions.

"The door-to-door stuff is great for local elections, but this is about big TV moments," said Mr Bertrand Dutheil de la Rochere, a senior campaign aide. "That's when people are going to make up their minds."