A row over whether only Greece should be allowed to label its cheese feta has reached the European Court of Justice.
Feta has been made in Greece for 6,000 years
The Danish and German governments are challenging a European Commission ruling which said Greece should have sole rights to use the name.
The Commission's decision gave the same legal protection to feta as to Italian Parma ham and French Champagne.
But critics of the judgement say feta is a generic term, with the cheese produced widely outside Greece.
The Commission's controversial 2002 ruling gave "protected designation of origin" status to feta cheese made in Greece, effectively restricting the use of the feta name to producers there.
From 2007 onwards, Greek firms will have the exclusive use of the feta label and producers elsewhere in Europe must find another name to describe their products.
The German and Danish governments argue that feta does not relate to a specific geographical area and that their firms have been producing and exporting the cheese for years.
"In our opinion it is a generic designation and we do not have any other name or term for this type of cheese," Hans Arne Kristiansen, a spokesman for the Danish Dairy Board, told the BBC.
Denmark is Europe's second largest producer of feta after Greece - producing about 30,000 tonnes a year - and exports its products to Greece.
It is concerned that the ruling could threaten the production of other cheeses in Denmark such as brie.
"It would cost millions if we wanted to introduce a new designation," Mr Kristiansen said. "That is just one of the costs."
The case will also have a major impact on Britain's sole feta producer, Yorkshire company Shepherds Purse Cheeses.
Judy Bell, the company's founder, said it would cost a huge amount to rebrand its product.
"If we lose we will have to go through a massive re-merchandising process and reorganisation," she said.
"We have never tried to pull the wool over anyone's eyes - it's very clear from the label that it's Yorkshire feta."
The original decision was a victory for Greece, where feta cheese is believed to have been produced for about 6,000 years.
Feta is a soft white cheese made from sheep or goat's milk, and is an essential ingredient in Greek cuisine.
Greece makes 115,000 tonnes, mainly for domestic consumption.
The Court is expected to reach a verdict in the case in the autumn.