Prime Minister Viktor Orban of Hungary, a hard-line champion of “illiberal democracy,” has for years taken swipes at the European Union and its officials.

On Wednesday, some in the European Parliament fired back — in song. After Mr. Orban finished his speech at the assembly in Strasbourg, France, progressive members started singing “Bella Ciao,” an Italian antifascist resistance song from the World War II-era.

Their singing, which lasted for less than a minute, was shut down by the president of the European Parliament, Roberta Metsola, as conservative members more politically in tune with Mr. Orban chanted slogans supporting him.

“This is not the Eurovision,” Ms. Metsola told the chamber, referring to the annual song contest. “Let’s respect the dignity of this house.”

The European Union — which Hungary joined in 2004 — has long been at odds with Mr. Orban for his right-wing nationalist stance on minority rights, immigration, the rule of law and other issues, including what Brussels sees as his sympathies for President Vladimir V. Putin of Russia. Mr. Orban is also the fiercest critic-from-within of the E.U.’s staunch backing of Ukraine, and an ally of former U.S. President Donald Trump.

Mr. Orban has often accused the E.U. of meddling in Hungary’s internal politics and promoting liberal values that he says differ from his country’s traditional, conservative ones.