The European Parliament's rejection of the French candidate for a top post in the EU Commission has opened a "major institutional crisis for Europe," France's Europe minister said Friday.

"It's first of all a major institutional crisis for Europe because without a French commissioner, the commission can't get to work," Amelie de Montchalin told France Inter radio.

"We need to work this out calmly, without anger, but Ursula von der Leyen needs to tell us what she expects of France," Montchalin added, referring to the new commission chief.

The parliament voted overwhelmingly Thursday to refuse the appointment of Sylvie Goulard for a broad economic portfolio covering industrial policy, defence spending, high tech and space. 

Goulard is under investigation by the EU Anti-Fraud Office over allegations she other MEPs from France's centrist MoDem party used European Parliament funds to pay assistants based in France.

French police also questioned Goulard last month over the claims.

The allegations forced her to resign as France's defence minister just weeks after her appointment in 2017, and she has already paid back €45,000.

But Goulard insisted that "I'm clean" during the first of two intense rounds of questioning by EU Parliament lawmakers this month following her nomination to the commission.

Her rejection for the key economic post was a blow to French President Emmanuel Macron, who slammed the vote as "petty" game-playing by MEPs.