Dutch MEP Sophie in 't' Veld warned Jean-Claude Juncker the fate of the European Commission hanged in the balance after the promotion of his former chief of staff Martin Selmayr.
The German civil servant sparked furious reactions from members of the European Union after he was hastily promoted to become the secretary-general of the Commission earlier this month.
Ms in 't' Veld cautioned Mr Juncker, saying the appointment threatened the credibility of European institutions and could force MEPs to withdraw their support: "The Commission will have to choose what is more important - the career of Mr Selmayr, or the credibility of the European Union, because the appointment of Mr Selmayr was a grave error and it must be corrected.
“That is a precondition for our continued support of this Commission.”
EUROPARLIAMENT TVEU News: Sophie in 't' Veld warned Juncker MEPs could withdraw their support after Selmayrgate
Talking to colleagues during the monthly parliamentary session in Strasbourg, the Dutch MEP lashed out against Mr Juncker for "sheepishly signing on the dotted line" to appoint his right-hand man to the role.
The rapid rise of Mr Selmayr under Mr Juncker’s leadership has been condemned by eurosceptics and europhiles alike and has lead to an independent watchdog considering whether to launch an investigation into the EC President’s decision.
Ms in 't' Veld continued: “‘Selmayrgate’ destroys all the credibility of the European Union as a champion of integrity and transparency in public administration.
“At times when public trust in the European Union is low, this is devastating. And the fact that the Commission remains deaf to criticism until today shows how disconnected it is from reality.
The Commission will have to choose what is more important
Sophie in 't' Veld
“I am left completely speechless at the scene of 28 powerful politicians, selected for the political leadership of this continent, but led by the nose by a civil servant. The political commission of Mr Juncker sheepishly signing on the dotted line - yes Mr Oettinger, that’s what you’ve been doing.
"If the commissioners are so easily intimidated by a civil servant if they act like helpless children when confronted by an unexpected staff decision, then how can we expect them to stand up for the European interests against Trump, for example, in a trade war?"
The new job for the Eurocrat, who is a close personal ally of Angela Merkel, comes despite being blamed for a series of high profile leaks about the Brexit process, raising questions of his suitability for the role.
The European Ombudsman, the Commission watchdog, said it had received two complaints about Mr Selmayr’s appointment and was considering whether to take action.
MEPs said the hiring process for his job left the EU a laughing stock that would prove more damaging than the existence of Eurosceptic parties.
Guy Verhofstadt insisted the way the European Commission has handled the appointment of Martin Selmayr is “bad for Europe”.
“Because you know it, I have no problem that Mr Selmayrs is very dedicated to the European. I think he’s a very competent civil servant.
“Now a problem that we have this with the way the Commission handled this. So something you have to do about this in any way because it is bad for Europe.”
Nigel Farage mocked the Commission’s decision to appoint Mr Selmayr claiming it was the “perfect stitch-up” to show European citizens the undemocratic nature of Brussels key political body.
He said: “The fast-track appointment of Martin Selmayer to a €20,000 a month job done without any openness, without any transparency.”
A Commission spokesman said: “Everything was done strictly by the book.”