By Alix Kroeger
BBC News, Strasbourg, France
In a foyer of the European Parliament, Poland is putting its argument for a tight definition of vodka in the most persuasive way it knows.
The argument is heating up over what may be defined as vodka
In front of a table laden with regiments of shot glasses, a queue of MEPs, parliament staffers and hangers-on forms and snakes around the room.
Glasses are filled and emptied in quick succession. The volume of conversation rises. Polish sausage and brown bread are on offer to soak up the alcohol.
The vodka being dispensed is made exclusively from potatoes or grain.
The Poles would like that definition to apply to everything sold as vodka across the EU. They are open to persuasion on sugar beet, but nothing else.
And they are not alone.
The Baltic countries - Estonia, Latvia and Lithuania - along with Finland, Denmark and Sweden are also backing efforts to tighten the legal definition in the EU's spirits regulation, being voted on in the European Parliament on Tuesday.
With Hungary and Slovenia prepared to back them, there are few predictions of how the vote will go.
"[The vodka belt countries] produce 70% of the EU's vodka," says Finnish MEP Alexander Stubb, "and we consume 70%, so we know what we are talking about."
Ranged against them are countries like Britain, France, Italy and Spain. They may not have a centuries-old tradition of producing vodka, but they have moved adroitly to get into a growing market.
Vodka has a distinguished pedigree in the EU - and beyond
They make vodka using less traditional materials, including sugar beet, citrus fruit and grapes.
Over the past few months, a proposed compromise between MEPs and the Council of Ministers, representing member states, has been hammered out.
MEPs will be voting on an amendment to the current regulation which would define vodka as "a spirit produced from grain or potatoes" or made from "other agricultural materials".
In that case, the bottle must say so on the label and list the raw materials.
But in the past two weeks, the compromise has come under strain. The vodka-belt countries are now backing a tougher amendment which would place strict limits on the use of the term vodka.
The Poles and the Finns say vodka is their heritage, but there is also a sound business case to be made.
While sales of other spirits remain flat, the value of the vodka market is rising.
British Conservative MEP John Bowis believes it should be a matter of "drink and let drink".
"I think it's really about, can we get a commercial advantage for our sort of vodka and close the market to the vodka made in Britain and many other parts of the EU," he says.
The European Vodka Alliance, which has been lobbying against the stricter definition, says it will take its case to the World Trade Organization if necessary.
But its spokesman, Chris Scott-Wilson, believes the Council of Ministers will reject any moves to restrict the vodka label, sending the regulation back to the European Parliament for a second reading if necessary.
Vodka can be made from grain, potatoes, sugar beet and fruit
Even Finnish MEP and vodka traditionalist Alexander Stubb admits it can be difficult to guess which vodka is made from what raw materials in a blind tasting. But he argues it is about quality.
"Call it something else," he suggests. "I don't want vodka to be a product which can be made of all agricultural products, which basically means you can use it to wash your windows."
This may not be the most urgent issue on the EU's agenda, but it is one which has exposed a cultural split: a regional division based on different tippling traditions.
"This is a battle of the vodka belt against the wine belt," says Finnish MEP Lasse Lehtinen. "In between lies the beer belt, which will get to decide."