Premier Silvio Berlusconi has promised to further explain his relationship with an 18-year-old woman at the heart of a political and personal scandal.

In an interview aired Monday with CNN, Berlusconi denied that he lied about his relationship with Noemi Letizia and said he merely tried to protect her and her family's privacy.

Berlusconi's wife, Veronica Lario, cited the premier's presence at Letizia's 18th birthday party in Naples in announcing a few weeks ago that she would divorce the 72-year-old.

The premier has said he knows Letizia's father through decades-old Socialist Party circles and that he attended the birthday party because he happened to be in Naples that day.

Opposition demands for clarification heated up Sunday after the left-leaning newspaper La Repubblica published an interview with Letizia's ex-boyfriend, Gino Flaminio.

Repubblica quoted Flaminio as saying Berlusconi had invited Letizia and several other young women to his Sardinian villa for a week over New Year's, and described phone calls he listened in on between Berlusconi and Letizia in which he said the premier asked her about her schooling, her interests and what her parents do.

Berlusconi told CNN there was nothing "negative" about the relationship.

"Now, they have accused me of having lied in my statements to newspapers, so to confront such an accusation I will react, I will explain exactly what the situation is and I will have once again all the Italians with me," he said. He said there would be a "boomerang" effect against the opposition once the truth comes out.

The interview was recorded Saturday, before Repubblica's interview with Flaminio was published. Officials said, however, that Berlusconi's position hadn't changed.

Berlusconi has said he would refer to the matter in parliament, although no date has been set and Berlusconi has said he needed to reflect first.

Opposition leader Dario Franceschini called for Berlusconi to clarify his relationship, and other leftist opposition leaders suggested Sunday a commission of inquiry was needed if the premier did indeed lie.

Berlusconi's aides have accused the opposition of fanning the gossip to try to hobble Berlusconi's Freedom People's Party in European Parliament elections next month. Berlusconi's allies have a comfortable majority in Italy's Parliament.

Letizia's father, Benedetto Elio Letizia, has said he would sue Repubblica and Flaminio for what he said was a report that was "seriously defamatory since it attributes to (Noemi) things never done, said, or thought" by her, the ANSA news agency reported.