British Prime Minister David Cameron, left, speaks with E.U. Commission President Jean-Claude Juncker in Brussels on Tuesday. (Thierry Charlier/AFP via Getty Images)

BRUSSELS — European Commission President Jean-Claude Juncker had a message for Britain on Tuesday. He delivered it in French.

With the impending British exit from the European Union, the polyglot Babel that has 24 official languages may soon strike English off the list, according to officials here, who note the change with a mixture of sadness and glee.

The European Union long conducted its business in French, even for decades after Britain and Ireland joined the bloc in 1973. But as the alliance expanded into Scandinavia and Eastern Europe, the momentum moved ineluctably toward English, the second language of choice for a far wider number of European citizens, diplomats and leaders. English is the common tongue at summits such as the one taking place Tuesday, with the leaders of E.U. member nations descending on Brussels for a grim, English-speaking dinner with British Prime Minister David Cameron.

But if Britain pulls out, the European Union will lose the only nation that has designated English as its official language inside E.U. institutions. Each country is allowed to pick one tongue, and Ireland and Malta — the other two E.U. nations that are predominantly English-speaking — chose Gaelic and Maltese, respectively. But they are tiny compared with the juggernauts of France and Germany, which supply the other two “unofficial” working languages of the European Union.

“Despite the vote, the British remain our friends,” Juncker told the European Parliament in French on Tuesday, forcing many of the 751 legislators to put on headsets to hear a translation. “As a result of the British vote, we’ve lost something very important.”

Juncker, a former prime minister of polyglot Luxembourg, typically speaks publicly in a succession of English, French and German, although English is his weakest language among the three. Other top E.U. leaders, including European Council President Donald Tusk, a former prime minister of Poland, confine their public comments to English.

Aides to Juncker said before his speech that the omission of English was a deliberate effort to send a message to Britain.

But others in Europe also were rooting for an end to English.

“English can no longer be the third working language of the European Parliament,” left-wing French politician and European Parliament member Jean-Luc Mélenchon wrote on Twitter.

“English is our official language because it has been notified by the U.K.,” Danuta Hübner, the chair of the Constitutional Affairs Committee of the European Parliament, said at a news conference on Monday. “If we don't have the U.K., we don't have English.”

Official E.U. rules require that all official communications be translated into all 24 E.U. languages — a vast operation that the European Commission says makes it the largest employer of translators in the world. If English were to be struck from the list, that would leave Britain to muddle through the difference between "adieu" and "au revoir" on its own.

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