The skyrocketing price of butter could kill off croissants, French bakers and pastry chefs are warning, amid growing anger from dairy farmers over the price of wholesale milk.

Croissants, the crispy, crescent-shaped breakfast bread cherished by the French, could soon become too expensive to produce, the country’s bakers warned on Tuesday.

The price of butter has risen by an eye-popping 92 percent in the year to May, with industry chiefs saying bakers are facing an “unsustainable” economic deficit by making croissants.

“The situation will unfortunately deteriorate in the coming weeks with a strong risk that butter will run out,” Fabien Castanier, the general secretary of the federation of French biscuit and cake-makers, said in a statement published on Tuesday.

Matthieu Labbe, a bakers’ industry spokesman, also raised the danger of butter shortages “by the end of the year”, if nothing was done about the problem.

The rise in the price of butter is blamed on falling milk yields in Europe, and especially in France, coupled with rising demand in both domestic and international markets.

The industry representatives said supermarkets, cafes and restaurants would have to “quickly” and “significantly” increase prices to keep pace with the sharply climbing cost of butter – an ingredient that represents up to one-quarter of croissants, brioches and other pastries.

‘Better sharing’

The croissant crisis ironically came at the same time French dairy producers protested over falling incomes.

Milk farmers blocked, and in some cases dumped cow manure, outside some dairy processing sites in western France on Tuesday, in order to draw attention to their plight.

“They have been facing a crisis for the past 30 months and the price they get for milk does not cover their production costs,” said Christiane Lambert, president of the powerful FNSEA French farmers’ union.

“We are asking for an increase of 30 to 40 euros per 1,000 litres of milk,” said Florian Salmon, who represents young dairy producers in the Iles-et-Vilaine department in western France. He said fellow farmers currently earned around 305 euros per 1,000 litres of milk.

Dairy farmers and executives also called on supermarkets to do more to help resolve the crisis.

“We are asking [supermarkets] to better share profit margins so that everyone wins, the stores, the milk processors, but also the farmers who always come last,” Régis Louazon, a dairy farmer who joined protests near the city of Rennes told AFP.