PARIS — France’s established parties are rallying around the man who helped shut them out of the presidential runoff, maverick centrist Emmanuel Macron – an alliance of convenience aimed at keeping far-right Marine Le Pen out of the Elysee Palace.

Support for Macron also poured in Monday from the seat of the European Union, as well as German Chancellor Angela Merkel and Jewish and Muslim groups troubled by Le Pen’s nationalist vision.

European stock markets surged, and France’s main index hit its highest level since early 2008, as investors gambled that the rise of populism around the world – and its associated unpredictability in policymaking – may have peaked.

For all the paeans to Macron’s unifying vision in divided times, it is now up to French voters to decide whether to entrust him with this nuclear-armed nation in the May 7 presidential runoff. Polls consider him the front-runner but that’s no guarantee that the French will come together to stop Le Pen the way they stopped her father, Jean-Marie Le Pen, from reaching the presidency in 2002.

France’s divided political mainstream, rejected by an angry electorate, united Monday to urge voters to back Macron and reject Le Pen’s far-right agenda.

Politicians on the moderate left and right, including French President Francois Hollande and the losing Socialist and Republican party candidates in Sunday’s first-round vote, maneuvered to block Le Pen’s path to power.

In a solemn address from the Elysee palace, Hollande said he would vote for Macron, his former economy minister, because Le Pen represents “both the danger of the isolation of France and of rupture with the European Union.”

Hollande said the far-right would “deeply divide France” at a time when the terror threat requires solidarity. “Faced with such a risk, it is not possible to remain silent or to take refuge in indifference,” he said.

Voters narrowed the French presidential field from 11 to two in Sunday’s first-round vote, and losers from across the spectrum called on their supporters to choose Macron in round two. Only the defeated far-left candidate, Jean-Luc Melenchon, pointedly refused to back Macron.

The contest is widely seen as a litmus test for the populist wave that last year prompted Britain to vote to leave the European Union and U.S. voters to elect Donald Trump president.

Le Pen, meanwhile, is hoping to peel away voters historically opposed to her National Front Party, long tainted by racism and anti-Semitism.

On Monday, she took a step in that direction, announcing she was temporarily stepping down as party leader, a move that appeared to be aimed at drawing a wider range of potential voters and was in keeping with her efforts in recent years to garner broader support from the left and right.

Choosing from inside the system is no longer an option.