ROME — Prime Minister Silvio Berlusconi stormed off the set of a state television show Sunday, branding the journalist interviewing him as a leftist, two days before a planned debate between the conservative leader and hischallenger, Romano Prodi.

"I'm getting up and leaving if you don't let me answer. Is that clear?" the prime minister said when the program's host, Lucia Annunziata, insisted that he answer her questions.

Annunziata, a longtime Berlusconi foe, resigned in 2004 as the head of thestate broadcaster, RAI, alleging that forces loyal to Berlusconi's government were trying to control the broadcaster. Berlusconi's three Mediaset networks are the main private TV rivals to RAI's three channels.

Annunziata now conducts a 30- minute newsmaker interview program on RAI called "In a Half-Hour." But on Sunday, Berlusconi walked out after 20 minutes.

When Berlusconi warned that he would leave if Annunziata demanded answers, she said: "I ask you not to go," and told him, "You can't dictate the rules."

His response: "I go if you don't let me answer. You can't tell me what to do. I don't decide for you, you don't decide for me."

After more bickering, Berlusconi stood up from his chair, reached over to shake Annunziata's hand and said: "All right. Goodbye, ma'am."

He told Annunziata she had given a fine example of being a person "who has prejudices and is on the left," and added, "You should be a little bit ashamed."

On Tuesday, Berlusconi and Prodi are set to debate each other on RAI and will square off a second time April 3, just before the April 9-10 vote.

Berlusconi complained on Saturday about the debate rules, calling them a "shame" for allowing journalists only 30 seconds to ask questions and requiring the leaders to finish their replies within three minutes.

Prodi's spokesman, Silvio Sircana,told SKY TG24 on Sunday that the important thing was that Berlusconi not walk off the set Tuesday evening.

The debates could affect the election results. Recent polls have given Prodi's center-left coalition a small edge over the center-right incumbents but also indicate there are undecided voters.

The prime minister in recent weeks has made a slew of appearances on talk shows on both his networks and those of state television.

Strict campaigning laws have forced the media to give equal space to Italy's plethora of political parties before the election next month. Berlusconi hascomplained that center-left opponents are refusing to share airtime with him and that radio and TV stations are reluctant to invite him alone. $@