ATHENS — A phone hacking scandal rocking Greece now has opposition politicians calling for the resignation of Prime Minister Mitsotakis, who is warning that Greece risks falling into the kind of political turmoil that is roiling Italy. 

At issue is the disclosure earlier this month that Greece’s state intelligence service was using Predator spyware to listen in on private phone calls made by the 43-year-old head of Greece’s resurgent Socialist party, Nikos Androulakis.

Mr. Mitsotakis, chairman of the center-right New Democracy party, has neither denied the surveillance nor admitted to any legal wrongdoing. Earlier this month he called the eavesdropping a “huge and unforgivable mistake” and fired the head of Greece’s national intelligence service, but he has studiously avoided explicitly stating who actually ordered it. 

This evasiveness is what led to a verbal sparring match on the floor of the Greek parliament yesterday. A former prime minister, Alexis Tsipras of the radical left-wing Syriza party, directly accused Mr. Mitsotakis of giving the order to monitor Mr. Androulakis.

It was Mr. Mitsotakis, though, who was the first to speak: “You are asking for [early] elections in this environment of instability; you are asking for the country to enter a two- to three-month adventure. Don’t you see what is happening in Italy? Think what would happen today with a caretaker government. You are calling for elections to pander to those who want instability.” 

Italy’s governing coalition, helmed by Prime Minister Draghi, collapsed last month amid suspicions it was undermined by Russian interference; snap elections are slated for next month. 

In a video posted to social media after the raucous parliamentary session, Mr. Androulakis characterized Mr. Mitsotakis’s discourse as “immersed in arrogance,” said the prime minister “claims that he cannot publicly state his reasons for the surveillance,” and accused him of “out-and-out despising the intelligence of the Greek people.” 

Mr. Mitsotakis dared Mr. Tsipras to censure his government over the handling of the phone hacking flap. It was not immediately clear if the Syrzia party would follow through, but even if it does such a move would mostly be symbolic because Mr. Mitsotakis’s New Democracy party holds a slim majority in Greece’s parliament.

As the investigation proceeds, expect more invective to fly. Case in point, yesterday’s remarks by an iconoclastic Greek politician who served as finance minister under Mr. Tsipras, Yanis Varoufakis. “Your prime ministership is over,” he said, addressing Mr. Mitsotakis directly. “You were a bubble and like a bubble you burst.” 

Mr. Varoufakis accused Mr. Mitsotakis of not only dodging questions about the surveillance but of governmental overreach. “It is not the prime minister’s job in our parliamentary government to be the institutional head of the intelligence service,” he said. “This would suit other regimes [but] not a democratic regime.”

The parliamentary session at Athens was moved up to August in light of the escalating crisis and the prospect of early elections. Should those come to transpire, an alliance of a resurgent Socialist party with Syriza, each with strong voter bases, could push the center-right government to the wayside. That is something that might be appreciated less in Brussels than in Moscow, given that the left in Greece is seen as less enthusiastic about NATO than the center-right.

Any discord in the EU bloc or among NATO alliance members is likely to be perceived by Moscow as a sign of weakness. As Washington must surely be aware, the sparks flying in Athens this week may eventually land outside Greece as well.