A senior politician with Poland's ruling party accused of drunkenly shouting "Heil Hitler!" at a German customs officer apologised on Friday and stepped down as head of his party's group in the European parliament.
Jacek Protasiewicz, by his own account, drank two bottles of wine on a flight from Warsaw to Frankfurt, and then got into an argument with the customs officer as he tried to leave the airport terminal.
The incident heaped embarrassment on Polish Prime Minister Donald Tusk, who has tried to build a new partnership with Berlin by putting to one side animosities that still linger after Germany's occupation of Poland in World War Two.
A statement from Tusk's Civic Platform party said Protasiewicz had informed the prime minister of his resignation from his roles as head of the party campaign for the European parliament election in May, and as leader of the Civic Platform faction in the European parliament.
"The resignation was accepted," the statement said.
It was not immediately clear if Protasiewicz would be able to continue in another role, as vice president of the European Parliament. Tusk said this week that Protasiewicz's behaviour at the airport had been unacceptable.
In a statement issued through Poland's state news agency on Friday, Protasiewicz offered apologies to anyone for whom "my inappropriate behaviour caused distress."
Germany's Bild tabloid quoted eyewitnesses as saying Protasiewicz had been drunk when he landed at Frankfurt airport, shouted "Heil Hitler!" at the customs officer and asked: "Have you ever been to Auschwitz?"
Protasiewicz had earlier this week defended himself, saying the customs official provoked him by addressing him rudely and shoving him.