French President Emmanuel Macron published a last-ditch plea for “citizens of Europe” to reject nationalism on Tuesday, issuing a continent-wide letter weeks before E.U. Parliament elections where right-wing parties are expected to surge.

“Nationalist retrenchment offers nothing; it is rejection without an alternative,” Macron warns in the letter, published in 22 languages and published in newspapers across Europe. “And this trap threatens the whole of Europe: the anger mongers, backed by fake news, promise anything and everything.”

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In particular, Macron points to Britain’s upcoming departure from the European Union as a symbol of what he calls “the crisis of Europe” and how the European project has failed to respond to “peoples’ needs for protection from the major shocks of the modern world.”

Macron was elected in 2017, beating out a right-wing opponent despite a nationalist-populist wave that swept the continent in partial response to the 2015 migration crisis. But Macron has seen his numbers sink at home, and protests from the gilet jaunes (yellow vest) movement almost weekly in French cities in response to his calls for an increase in taxes to combat climate change.

Beyond those challenges, Macron has cast himself as a defender of the international order on the world stage, giving strong denunciations of nationalism in both Congress and the United Nations. But even that has come as nationalist-populist governments have strengthened their grip on power in countries such as Hungary and Italy -- with whom Macron has feuded in recent months on the subject of migration.

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Right-wing and nationalist-populist parties are expected to do well in upcoming E.U. Parliament elections in May, something that would dent the E.U.’s internationalist world view, and move the body to a more right-wing position on issues such as immigration and trade.

Macron was elected as a centrist, and has regularly tried to find a middle ground between left and right. There were signs of that in his Tuesday letter, where he appeared to throw a bone to Europeans concerned about immigration, and promised a “rethink” of the Schengen Area -- a zone in which countries abolish their internal borders so as to allow free movement.

“We therefore need to rethink the Schengen area: all those who want to be part of it should comply with obligations of responsibility (stringent border controls) and solidarity (one asylum policy with the same acceptance and refusal rules),” he writes.

“On the issue of migration, I believe in a Europe that protects both its values and its borders,” he later added.

But citing again the example of Brexit, he calls on Europeans to act and pushback against the nationalist surge on the continent.

“We cannot let nationalists without solutions exploit the people’s anger. We cannot sleepwalk through a diminished Europe,” Macron says. “We cannot become ensconced in business as usual and wishful thinking.”

Macron’s warning comes just a few weeks after left-wing billionaire George Soros warned that Europe is “sleepwalking into oblivion, and the people of Europe need to wake up before it is too late.”

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“The first step to defending Europe from its enemies, both internal and external, is to recognize the magnitude of the threat they present,” he writes. “The second is to awaken the sleeping pro-European majority and mobilize it to defend the values on which the EU was founded.”

“Otherwise, the dream of a united Europe could become the nightmare of the 21st century,” Soros, known for his funding of left-wing causes, wrote.