When 10 new countries join the European Union on 1 May, they bring with them an extra nine languages to add to the EU's existing 11.
There could even be 10 new tongues, for if Greek and Turkish Cypriots vote for reunification before then, Turkish will become the EU's 21st language.
Translators, builders and electronics suppliers are busy ahead of 1 May
How will it cope? Even with 20, Europe's tower of Babel is creaking.
Twenty languages gives a total of 190 possible combinations (English-German, French-Czech, Finnish-Portuguese, etc), and finding any human being who speaks, for example, both Greek and Estonian or Slovene and Lithuanian is well-nigh impossible.
To get round this problem, the parliament will use much more "relay translation", where a speech is interpreted first into one language and then into another - and perhaps into a fourth or fifth.
Clearly the scope for mistakes in this game of Chinese whispers is huge.
"If I'm first in the chain, and make a mistake, then everyone else down the relay makes the same mistake - or worse," Jana Jalvi, one of the new Estonian recruits says.
The need for translation already takes away the cut and thrust of a normal parliamentary debate.
When the Italian Prime Minister, Silvio Berlusconi, last year likened a German MEP to a Nazi camp guard, it took several seconds before the German realised he was being insulted and pulled off his headphones in disgust.
But the rule is that every language must be provided.
"The European Parliament is the one place you can't expect people to speak a foreign language," Patrick Twidle, who is in charge of recruiting new interpreters, says.
"People are elected not because of their language skills but to represent their political constituency."
Before and after
European Commission has 1,300 translators
They process 1.5 million pages a year
They cost the EU 550 million euros
After 1 May, staff will almost double in size
They will translate 2.5 million pages a year
Their budget will be over 800 million euros
The European Commission already has 1,300 translators, who process 1.5 million pages a year in the EU's 11 languages.
In two years that is expected to rise to almost 2.5 million pages - and the staff, based in two enormous buildings in Brussels and Luxembourg, will almost double in size to cope with the output.
The cost will rise from roughly 550 million euros today to over 800 million euros after enlargement.
Is it worth it?
Juhani Lonnroth, the Finn who runs the translation service, has done his sums.
"Translation costs less than 2 euros per citizen, so it is less than a cup of coffee or a ticket to the cinema," he says.
"I think it's worth it because it is part of democracy."
MEPs nonetheless last week debated whether it might not make sense to have just one official language for the EU.
An Italian MEP, Gianfranco Dell'Alba, wondered if all MEPs should have to learn a neutral language like Esperanto.
The obvious choice, in fact, would be English, which is more widely spoken as a second language than any other.
But the French - who have the parliament on their soil and who, after all, were founder-members of the EU - were outraged by the very suggestion.
They are already miffed at the slow easing-out of their language as the chief means of communication in the European Commission, where English is steadily gaining ground.
EU commissioners from the new member states are being offered a free crash course at a chateau in the south of France, while lower-level civil servants will get free French lessons in Brussels.
Over 1,000 have already availed themselves of the opportunity.
Meanwhile, translating has become the EU's biggest boom industry.
It is not just the official institutions that require documents in their own languages, but all the associated lobbying companies and consultancies.
Builders have been constructing new cabins for the interpreters in all the meeting rooms of the European parliament - in Brussels and in Strasbourg.
Electronics suppliers are cashing in on the demand for more sophisticated mixing desks to make sure the correct language gets channelled to each set of headphones in the enormous chamber - including those provided for members of the public.
"It's very exciting," says Mari-Liis Aroella, an Estonian interpreter.
"We've been waiting so long for this moment, and finally it's happening."
She looks exhausted after two hours of intense concentration during a practice session, simultaneously translating a debate about the future EU constitution, full of expressions that most citizens would be hard put to understand in their own language.
And they are planning for an even grander future.
There are already 27 interpretation booths ranged around the parliamentary debating chamber, for soon there will be Romanian and Bulgarian - not to mention perhaps Croatian and Macedonian.
The tower grows and grows.