A key parliamentarian in the anti-immigration Northern League party has likened Italy's first black minister to an orang-utan.
Cecile Kyenge, an eye surgeon and Italian citizen born in the Democratic Republic of Congo, has repeatedly suffered racial slurs since her appointment as integration minister in April.
Roberto Calderoli, vice-president of Italy's Senate, said on Saturday at a political rally in the northern town of Treviglio: "I love animals - bears and wolves, as everyone knows - but when I see the pictures of Kyenge I cannot but think of, even if I'm not saying she is one, the features of an orang-utan."
He reportedly said the success of Kyenge encouraged "illegal immigrants" to come to Italy and she should be a minister "in her own country".
Yesterday, politicians, including some from his own party, lambasted Calderoli, with some calling for him to resign as Senate vice-president. In an official statement and on Twitter, Prime Minister Enrico Letta said the comments were unacceptable.
"They go beyond all limits. Full solidarity and support to Cecile. Forward with your and our work," Letta said.
Asked about the comments, Kyenge said it was not up to her to call on Calderoli to quit but she hoped politicians would "reflect on their use of communication".
Since being made minister in Letta's fractious coalition government, Kyenge, 48, has been the target of criticism from the league. Some has been directed at her policies, particularly her desire to change a citizenship law to make it easier for Italian-born children of foreigners to gain full nationality before they are 18.
Calderoli, 57, yesterday insisted he had been joking.
"I was speaking at a rally and I made a joke, an unfortunate one perhaps," he said. "I did not want to cause offence and if minister Kyenge has been offended I apologise, but my joke came in the context of a much broader political speech that criticised the minister and her politics."
In 2006, he quit government after going on TV in a T-shirt emblazoned with cartoons of the Prophet Mohammed - a move credited with sparking fatal riots outside the Italian consulate in Libya. After Italy's soccer team beat France in the World Cup that year, he said the opposing side was made up of "niggers, Muslims and communists".
Additional reporting by The Guardian