One cabinet minister conceded that “a democratic accident is possible this time”. 

“I’m like the phoenix rising from the ashes,” Ms Le Pen said last week.

Before the rally, pro-Macron MP Frédéric Descrozaille told the Telegraph that Ms Le Pen had led “an absolutely impeccable campaign”.

“That said, her programme would be a catastrophe, notably on the international level. All the effort that we have put in over the past five years to restore France’s credibility to attract investors and with our partners and allies and in terms of leadership would go up in smoke if she was elected,” he said. 

At the rally, Macron supporters hoping to boo his far-Right rival were shut down by the president from the outset: “You know my rules: in here we don’t whistle anyone, ever.” 

But in the closing moments of his two hours-and-a-half speech, he took direct aim at both Ms Le Pen and her far-Right rival Eric Zemmour.

“We have got used” to extremists’ discourse, he warned, saying that “hatred and alternative truths have become trivialised”.

“They can decide to leave the euro in the morning and return to Europe in the evening without anyone pointing out the incoherence,” he added, in a swipe at Ms Le Pen’s U-turn on leaving the euro and EU.

“Don’t boo them, fight them with ideas with respect,” he said. “Their programme would ruin modest savers, collapse their purchasing power and lead to the bankruptcy of their pensions but nobody gets worked up. We’ve got used to it.”