A row over the new EU Commissioner for Transport and Tourism, Frenchman Jacques Barrot, has shaken the beleaguered European Commission, just as it starts work and licks its wounds after the debacle over Italy's Rocco Buttiglione.
The spotlight fell on Mr Barrot last week when Nigel Farage, leader of the UK's anti-EU UKIP party, revealed that the Frenchman had been convicted for embezzling party funds.
It has been a bumpy ride to Brussels for Mr Barrot
Now the British leader of the European Liberal Democrats has joined UKIP's calls for Mr Barrot to resign.
His failure to reveal a past conviction, Graham Watson said, "constitutes an unacceptable abuse of trust".
"Mr Barrot is seriously compromised by the revelation of his conviction and suspended jail sentence for conduct that is illegal in many EU member states," Mr Watson added.
Mr Barrot, 67, a close ally of French President Jacques Chirac, received a suspended jail term in a party funding case in 2000, but it was automatically erased by a 1995 presidential amnesty.
Under French law, no reference may be made to such a sentence, which carries no criminal record.
Mr Barrot, of the ruling centre-right Union for a Popular Movement, was never barred from holding public office.
He was one of many politicians from all major parties who got into trouble for illicit funding dating back to a period before 1991, when France had no law regulating campaign financing.
Mr Barrot was for two years leader in the French National Assembly, the
lower house of parliament, before he joined the EU Commission in March to replace Michel Barnier, who had been named French foreign minister in a
Mr Barrot previously served as social affairs minister in the conservative government of former French Prime Minister Alain Juppe. He is married and has three children.
He has called for the allegations to be withdrawn.
"He must take back what he said, so that everything can be fully clarified, so that parliament can be sure of the truth," Mr Barrot said of Mr Farage, according to the French daily Le Monde.
Mr Barrot has promised to clear things up, and in a letter to MEPs released on Monday he said he had nothing to hide.
"I had nothing to cover up and I absolutely did not look to cover up anything from the European Parliament, which I profoundly respect," he wrote.
Mr Barroso too has written to the European Parliament, clarifying the facts surrounding the 2000 conviction and insisting that the Frenchman will make an "excellent" EU commissioner.
But he did admit that he would have preferred to know about the case before, rather than after the commission's inauguration.