The European Commission enters uncharted political territory with the appointment of Martin Selmayr as its new secretary-general.

The 47-year-old German lawyer — a product of the European People’s Party machine and protégé of leading German and Luxembourgish center-right politicians — is arguably the most openly political person to hold the top civil service job at the Commission.

One potential fallout from Wednesday’s appointment is the escalation of the institutional war of attrition between the Commission and its co-equal institution, the European Council. As Commission President Jean-Claude Juncker’s powerful chief of staff, Selmayr has clashed with his counterpart across Schuman Square, the Pole Piotr Serafin, as well as his boss, Council President Donald Tusk, who represents the 28 member countries in Brussels.

The promotion also raises concerns about the prominence of Germans in top Brussels jobs.

Selmayr engenders loyalty and respect from mentors he cultivates intensively and underlings whom he helps place in top jobs around the Commission.

The biggest unknown facing Selmayr in the longer term is who will get the Commission presidency once Juncker leaves at the end of 2019. If it’s an ally, he and presumably Juncker’s legacy are secure. But with a different kind of crew in charge at the Berlaymont building, the potential for trouble is obvious. Selmayr serves at the pleasure of the College of Commissioners.

This appointment was pushed through by Juncker, his latest mentor, in a way that surprised and angered many people in the Brussels machinery.

Most commissioners were told only minutes before the College meeting about the promotion, according to people familiar with the events of Wednesday morning.

The Selmayr and Juncker method is unusually blunt by the standards of Brussels, which cherishes consensus and wonkish deliberation on even the smallest matters. But then Juncker turned up in the EU capital pledging to run a more “political” Commission. On that, with Selmayr as his wingman, he has delivered.

In the summer of 2016, weeks after the U.K. voted to leave the EU, Juncker and Selmayr moved without consulting the College to make their most important appointment to that point — that of Michel Barnier as the chief Brexit negotiator. The decision angered several commissioners, and was cited by the Bulgarian Vice President Kristalina Georgieva as one reason for her to leave the Commission for a top job at the World Bank.

The Martin method

Andrew Duff, a former Liberal MEP and EU constitutional expert, said Emile Noel — the longest-serving Commission secretary-general (1959-1987) — “would be worried” by the move of an EPP stalwart into that job.

Selmayr started out at the Bertelsmann Foundation, a breeding ground for center-right operatives on the European stage, and worked closely with the German Christian Democrat Elmar Brok, the longest serving member of the European Parliament. He went over to the Commission to be a press spokesman on digital matters, rising quickly from there.

He engenders loyalty and respect from mentors he cultivates intensively and underlings whom he helps place in top jobs around the Commission.

Paraskevi Michou joined the Commission in the 1992 and was a middle manager at the digital department as late as 2010 when Selmayr finished his time there. Next week she will become director-general for migration and home affairs.

Mina Andreeva started as an intern in the same digital department working with Selmayr. Several years later she has become the Commission’s deputy spokesperson when she was just over 30 years old.

Whether over appointments or policy, Selmayr hasn’t shied from taking on commissioners, knowing that Juncker stands behind him.

And more than any previous holder of the office, he is media savvy, using the press to get his messages out, mostly under the cover of anonymity, and staying active on Twitter.

Back in 2014, he rewrote would-be Trade Commissioner Cecilia Malmström’s written testimony to the European Parliament without her permission, then leaked it to the media, as the Financial Times reported at the time.

British officials blame him for leaking details of U.K. Prime Minister Theresa May and Juncker’s disastrous dinner date in London last summer.

Germans rising

His adversaries have called him everything from “poisonous” to “Ho Chi Minh,” but even with them he gets respect for his fearlessness, big vision, work ethic and long-term thinking.

An immediate consequence of the Selmayr appointment is to highlight the number of Germans in the top civil service jobs in the EU institutions. That concentration of national perspective, if not necessarily national interest, worries many in Brussels.

“But how can Martin stand up to the president when he is, in effect, the president?” — European Commission official

Helga Schmid is secretary-general of the European External Action Service, the EU’s foreign policy arm, and Klaus Welle holds the same title at the European Parliament. Jens Weidmann, who runs the Bundesbank, is a favorite to take over at the European Central Bank next year.

The Council is run by a Dane, Jeppe Tranholm-Mikkelsen, who replaced the German Uwe Corsepius. Selmayr replaces the Dutchman, Alexander Italianer.

But the erosion of walls between civil servants and their political masters may be the larger legacy of Wednesday’s tempest in the Brussels bubble.

“Catherine Day [the powerful secretary-general who served before Italianer] was a brilliant guardian of the Commission procedures, able to serve the president but stand up to him,” said one Commission official. “But how can Martin stand up to the president when he is, in effect, the president?”

David M. Herszenhorn contributed reporting.