The European Commission President urged his Brussels colleagues not to “underestimate” or deal with far-right parties in order to win control of the European Parliament after next week’s bloc-wide elections. Mr Juncker, who is expected to step down as the EU’s top official in November, said the EU would be “incapacitated” if his successor used populist support to shore up their position. He even claimed he would urge his Christian Social Union party in Luxembourg to quit the European People’s Party if the centre-right, EU-wide group builds a “compromise with extremists from the right”.
In an interview with Austrian newspaper Der Standard, Mr Juncker said: “I see this election as serene and calm, but deeply concerning, because I see the margins of the political spectrum questioning the European project.
“What happens to the next Commission will depend on the way the next European Parliament is put together.”
The 64-year-old former Luxembourg prime minister added: “The extreme-right is the greatest danger in the face of the mixed situation.
“If the forces of the extreme-right and extreme-left have too much influence in the European Parliament, then all the debates may not be fully dominated but strongly influenced.”
In a warning to his pro-Brussels colleagues, Mr Juncker recalled the words of Marine Le Pen, the leader of France’s far-right National Rally.
In July 2014, Ms Le Pen told the newly crowned Commission President that her party would vote against and disrupt Brussels decision making.
“A Commission that relies on the votes of the extreme right or left would be incapacitated,” Mr Juncker said.
“It would alway have to take into account the slogans at the beginning. One should not underestimate the danger from the right.”
Mr Juncker fears that mainstream, pro-EU parties are being forced to adopt the rhetoric of populist movements in order to maintain their vote share.
“The classic European parties make rhetorical compromises with the extreme-right, and then the image of Europe will darken,” he said.
Asked if Manfred Weber, the EPP’s lead candidate for the Commission presidency, used the support of populists to secure the top job, Mr Juncker claimed he would quit his party membership.
“If that happened, I would not quit membership in the Christian Social Union, in Luxembourg,” he said.
“But I would ask my party to leave the EPP, it can not and must not compromise with extremists from the right.”
While the EPP is expected to win the most seats in the new European Parliament, support for traditional parties is waining ahead of the May 23-26 vote.
The EPP is expected to win around 180 MEPs, which is a loss of 36 seats from their current group in the European Parliament.
For the first time, the EPP and the Socialists, who have dominated the Parliament for 40 years, could lose a combined majority for a grand coalition with them projected to only take 43 percent of the seat between them.
Populist parties, such as League in Italy and the National Rally, are expected to double their seats in the vote.