When EU Commission President Jean-Claude Juncker announced at a last-minute news conference that his top aide was being promoted, it initially caused few ripples outside the so-called "Brussels bubble".
But the sudden elevation of Martin Selmayr to the position of chief civil servant of the 30,000-strong commission has now sparked a row that involves allegations of cronyism and a lack of transparency.
The controversy over Selmayr, a German former lawyer dubbed the "Monster" for his forceful style, could even paralyse reforms to the post-Brexit EU and provide fuel for eurosceptic parties, diplomats and analysts warn.
"It's a bad sign," Sebastien Maillard, head of the Jacques Delors institute, a think-tank named after the legendary Frenchman who led the European Commission from 1985 to 1995, told AFP.
Former Luxembourg prime minister Juncker's reign is in its dying days as he has said he will step down next year, and Selmayr's promotion showed that people were already jostling for jobs, said Maillard.
"Selmayrgate" threatened to distract the commission just as the EU was hoping that French President Emmanuel Macron and German Chancellor Angela Merkel could push on with reforms.
"It's entering its final cycle too early at a time when it has to keep acting and making proposals", a senior diplomat from a leading EU state told AFP.
- 'Devastating' -
The row centres on what critics say was effectively an overnight promotion for the 47-year-old Selmayr, Juncker's former chief of staff, on February 21.
Juncker held a press conference with less than an hour's notice to name Selmayr as the new secretary general of the commission, the powerful executive arm of the EU.
But it later emerged that Selmayr, Juncker's gatekeeper and enforcer for the past four years, had been first appointed deputy secretary general earlier that morning after applying along with one other candidate.
Minutes later the existing secretary general, Dutchman Alexander Italianer, resigned and Juncker effectively presenting it as a done deal to the commissioners, only two of whom had been warned in advance, sources told AFP.
The row then spiralled, with the veteran French journalist Jean Quatremer leading what at times resembled a rebellion in the normally well-mannered European Commission press room.
The EU's ombudsman has now confirmed it has received two complaints about the matter and was analysing them.
The affair has been a chance for revenge for the many enemies that Selmayr amassed with his take-no-prisoners style and reputation as a master of the dark arts of political spin.
Guy Verhofstadt, the Brexit coordinator in the European Parliament, warned that Juncker's commission could face the same fate as the one led by Jacques Santer in 1999, which had to stand down in a corruption row.
Sophie in 't Veld, a leading liberal member of the European Parliament added about Selmayrgate that "at a time when public trust in the European Union is low, this is devastating."
- 'Rasputin' -
In Britain too there has also been a certain schadenfreude over his woes, after he was widely blamed for leaking sensitive details about Prime Minister Theresa May's weak position in Brexit talks.
The British press have previously dubbed him "Rasputin" after the influential but mad monk attached to the Russian royal court in the early 1900s, and the "Beast of Berlaymont" after the EU's hulking 1960s headquarters.
Juncker himself called Selmayr his "monster", although that was reputedly because of the German's capacity for hard work.
MEPs will now vote in April on Selmayr's appointment, after the European Parliament's budgetary control committee investigates his promotion.
But any move to oust Selmayr will however likely be blocked by the European People's Party, the centre-right group that is the biggest in the parliament and which counts Juncker and Merkel among its members.
"It's a purely political decision," an EPP member told AFP on condition of anonymity.
The EU's member countries are also keen to stay out of the row, which comes at a bad time.
Now that Germany has emerged from six months of political limbo, the EU is keen to use a window of opportunity for reforms to counter a tide of populism that led to the Brexit vote and has since seen eurosceptics surge in Italy.
"The European Commission mustn't become a lame duck just because of a row over a bureaucrat's job," Maillard warned.