EU Commission President Jean-Claude Juncker was so stupefied after Hungarian Prime Minister Viktor Orban attacked his migration policies that he publicly muttered "I cannot believe what I read." When Orban's party later targeted him in a virulent election poster campaign, Juncker was again dumbfounded, saying "You can't really act against lies."
Enemies from opposing camps? No, they belong to the same EPP Christian Democrat group, the dominant force in the European Parliament, and should, in theory, be close allies in May's European Union election.
Instead, this political fratricide is front and center in this massive exercise of democracy, which spans 27 nations and involves close to half a billion people. The May 23-26 European Parliament vote could prove to be a tipping point in post-war European politics.
Some traditional political powerhouses might start to crumble, allowing extremist, populist parties to gain more clout and throw a new wrench into the EU's political machinery.
"We've never seen something like this in EU elections," said European politics Professor Hendrik Vos of Ghent University about the abrasive election climate.
The EU parliamentary election is run as national ballots in 27 member states. National political parties with common ideology then unite in EU-wide groups like the center-right EPP, the center-left S&D Socialists and the liberal, pro-business ALDE.
Over the years, the major political groups started looking at adding unattached national parties to expand their bases. Even if these newcomers might not be as close to their core values, they still could boost their seat totals in Parliament.
Some factions, however, have developed sharply contrasting agendas within their groups and can vary as widely as the geographic spread from Finland to Hungary to Portugal. Some could now splinter off — like Orban's staunchly anti-migrant, right-wing Fidesz party — weaken the center and reinforce the fringes.
The EPP, for example, welcomed a populist Italian, Silvio Berlusconi, two decades ago. Orban's Fidesz party followed soon after. Other groups also face similar internal trouble — the ALDE with populist Czech leader Andrej Babis, who has been accused of misusing EU farm subsidies, and the S&D with Romania's Social Democrats, who critics say are weakening the judiciary's fight against corruption.
But nowhere has it produced political fireworks like at the EPP.
Orban was first embraced for his anti-Communist credentials but over the years turned into an anti-immigration populist calling for an "illiberal" society with autocratic leadership, something that increasingly jarred with EPP values.
It came to a boil over the past month when Orban fired up his anti-Brussels rhetoric portraying Juncker as conniving to keep nations like Hungary under their thumb and opening EU borders to all migrants. He plastered Budapest with posters showing Juncker as a gloating force of evil.
"I consider the formulations in the poster campaign in Hungary against Jean-Claude Juncker, which is meeting with incomprehension in large parts of the EPP, unacceptable," Austrian Chancellor and EPP heavyweight Sebastian Kurz said Friday.
Now the EPP faces a political dilemma: should it jettison Orban over principles, whatever the consequences, or try to keep him in a chokehold so he won't unite with other anti-EU populists?
"In these new dynamics there are new opportunities," noted Italian political analyst Alberto Alemanno.
Since the last EU election in 2014, Britain has voted to leave the EU and Italy and Austria have government coalitions that include the far right. Over a dozen EU nations have fragile minority governments and Poland has turned as hostile toward Brussels as Hungary.
"After the fall of London, Rome, Warsaw, Budapest, or Vienna into the hands of anti-European and/or xenophobic forces, we no longer speak of the 'enemy at the gate' but of the 'enemy inside the gates,'" wrote Jose Ignacio Torreblanca for the European Council on Foreign Relations.
And all this comes at a time when the European Parliament now has more powers. All too long a posh retirement post for over-the-hill politicians, the parliament is now an effective decision-maker with a real say on everything from Brexit to anti-pollution regulations.
The first projections for the 705-seat legislature, produced this week by the parliament itself, show the EPP Christian Democrats struggling with 183 seats, the S&D Socialists losing big to land at 135 seats and their grand coalition short of a majority for the first time. Populists would gain more clout during the upcoming five-year session.
The influential VoteWatch Europe think tank said "right-wing nationalists are set to gain, although they are likely to fall short of getting over 25 percent of seats."
But it said a united group of right-wing nationalists could become the second largest group in the legislature.
So far, populist and extreme parties have added decibels and eyebrow-raising rhetoric to the EU plenary but have had precious little impact on parliament events.
But with higher numbers and better coordination, the anti-EU forces could start weighing in more on decision-making in Europe and battle back against pro-EU French President Emmanuel Macron's vision of an ever-closer union.
That would be music to Orban's ears and a massive defeat for Juncker.
Since Juncker is not running for another term as Commission president, the vote in May could be the last round of their fight. That round is not over and Juncker wants to protect his pro-EU legacy.
"I'm not giving in. I'm not like that. I want to be exactly the opposite of that," Juncker said.