BRUSSELS/STRASBOURG, France (Reuters) - The European Parliament savaged EU Commission President Jean-Claude Juncker on Monday for promoting his chief aide to the top of the EU civil service, saying it smacked of cronyism and would fuel mounting public distrust.

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Lawmakers from across the spectrum, including Juncker’s conservatives, criticized the sudden appointment of his chief-of-staff, Martin Selmayr, to be secretary-general of the Commission, an affair that has become known in Brussels as “Selmayrgate”.

“Frankly, we have shot ourselves in the foot,” Francoise Grossetete of Juncker’s centre-right European People’s Party said, arguing that the decision to pick Selmayr, during a closed-door meeting on Feb. 21, was “grist to the mill” for eurosceptics.

Selmayr, a 47-year-old German lawyer known as a hard-driving devotee of European integration, is both feared and admired by senior EU officials. In his new position he is in charge of the day-to-day running of the 33,000-strong EU civil service.

Brexit campaigner Nigel Farage said his appointment was “the perfect stitch-up”, an example of “nepotism” that showed Britain was right to be quitting the European Union.

The Greens threatened to hold up approval of the Commission’s budget and the Liberal group demanded Juncker reverse the appointment.

Their leader, former Belgian premier Guy Verhofstadt, evoked the case of Juncker’s compatriot Jacques Santer, whose Commission was ousted in 1999 over a nepotism scandal.

“If the Juncker Commission is not careful, it will have the same fate,” Verhofstadt tweeted.

The European Ombudsman said it had received two complaints about Selmayr’s appointment and was analyzing them. The Ombudsman has limited powers but has a record of shaming the Commission over perceived failings, such as conflicts of interest.

Juncker, a former Luxembourg premier whose five-year term ends in 18 months, has defended the appointment as one he and his 27 fellow commissioners were entitled to make. It is not subject directly to parliamentary oversight and could be overturned by Juncker’s successor, who will be chosen by EU national leaders.

Several lawmakers criticized Juncker for failing to appear before parliament, sending Guenther Oettinger, the commissioner who runs personnel issues, instead.

“We have done everything by the book,” Oettinger said, adding Selmayr was “100 percent suitable” and that his German nationality and political allegiance to Europe’s powerbroker Chancellor Angela Merkel were of no consequence.

“We have acted within the letter of the law,” Oettinger said.

But several lawmakers said the spirit of transparency had been breached.

Werner Langen, who, like Oettinger and Selmayr, is a German Christian Democrat, said the affair reminded him of “19th-century secret bureaucracy”.