French voters urged to shun Le Pen in run-off

They spoke after Macron won the vote by a larger margin than expected — some 28 percent compared to Le Pen's 23 percent, exit polls said.

But Le Pen, a hardline eurosceptic and economic nationalist with close Kremlin ties, still poses a threat in the run-off on 24 April, prompting the calls for a cordon sanitaire.

"I will vote in conscience for Emmanuel Macron to impede Marine Le Pen from coming to power and the chaos that would result," Pécresse said after the exit polls, according to French media.

Hidalgo, Jadot, and Roussel issued similar messages.

"So that France does not tip into hatred of all against all, I ask you gravely to vote on April 24 against the Marine Le Pen's far right with a ballot for Emmanuel Macron," Hidalgo said.

But for all their support, they have little to offer the liberal incumbent.

All of them did badly — gaining just 5 percent or less in Sunday's — and Pécresse's political party colleague and star, Eric Ciotti, did not join her anti-Le Pen call.

On the far-right side, self-avowed racist Eric Zemmour and sovereignist Nicolas Dupont-Aignan are expected to urge their voters to back Le Pen.

But Zemmour did much worse than expected, with just 7 percent, while Dupont-Aignan got 2.3 percent.

And all that means the far-left Jean-Luc Mélenchon — who came third with 20 percent Sunday — might end up playing a kingmaker role.

Mélenchon's politics is also an anathema to Macron's economic liberalism and staunch pro-EU views.

But while Mélenchon did not tell his supporters to vote for Macron in the second round, he still found himself closer to the president than to Le Pen in terms of basic values.

He urged his backers four times in one short speech not to vote for Le Pen.

"You should not vote for Mrs Le Pen", Mélenchon said. "Le Pen should not get a single vote", he added.

"I know your anger [about social inequality in France], but don't give into it. Don't let anger make you do things that would be irreparable," Mélenchon said.