(By Kate Carlisle) Rome, July 16 - A row over a Northern League party bigwig likening Italy's first black minister to an orangutan is hardly finished, a source from Premier Enrico Letta's office said on Tuesday, rebutting League leader and Lombardy Governor Roberto Maroni's assertion that it was. On Monday Letta called on Maroni to intervene over comments Deputy Senate Speaker Roberto Calderoli, a League member, directed at Integration Minister Cecile Kyenge at the weekend. Letta said it was not in anyone's interest to draw out what he described as a "shameful" episode. Maroni said Tuesday that the case had blown over after he refused to ask Calderoli to quit. "It has not blown over at all," said the source. "The slip-up was just that of a leader who cannot get Calderoli to quit as Deputy Senate Speaker. "Unfortunately, he does not hold a position (Calderoli) that can be put to a no-confidence vote. But by acting in this way, Maroni is an accomplice to the insult to Minister Kyenge". Calderoli addressed the Senate on Tuesday and again apologised for his "offensive" remarks, saying he would send Kyenge flowers. "I got carried away and I committed a grave error, very grave because I shifted the attention from the political sphere to the personal... I asked her (Kyenge) to forgive me, and I ask the same of the Senate," Calderoli said. But he did not give the resignation that Letta and Kyenge's Democratic Party (PD) had called for. He said he would have resigned if the majority of the parties in parliament had asked him to. Calderoli and his party frequently adopt extreme stances on migration issues. Lower House Speaker Laura Boldrini on Tuesday said Calderoli was guilty of "intolerable backwardness". "No one can remove him. It can only be his decision," said Boldrini, after Maroni rejected a call to intervene from Letta. "People who hold institutional roles cannot say just anything that crosses their minds. "They have to be up to the role. If he cannot control himself he is not capable of doing his job". PD councillors from the northern town of Ferrara, Paolo Calvano and Simone Merli, filed a criminal complaint against Calderoni with the Bergamo prosecutors office for aggravated defamation and incitement of racial hatred. On Monday, PD Senator Sergio Lo Giudice responded with an official complaint filed with Italy's anti-racial discrimination body against the deputy Senate speaker. "This morning I sent Italy's National Office against Racial Discrimination (UNAR) a formal communication about the disturbing incident of racially motivated offenses against Minister Cecile Kyenge," Lo Giudice said. "I felt that it was my duty to report this episode that, due to the institutional source it comes from, is particularly serious and reflects conduct based on the idea of racial superiority and discrimination on the basis of ethnic backgrounds".