They were left battered by farmer Jose Bové's attacks on McDonald's and bruised by the birth of the "freedom fry". But yesterday the French and the Americans proved they had the stomach for another gloriously messy food fight.

Less than a week before it leaves office, the Bush administration has sparked anger across the Atlantic by tripling the import duty rate on roquefort cheese to 300%, a move which the US hopes will "shut down trade" in the sheep's milk product by making it prohibitively expensive.

The decision, part of Washington's attempts to force the EU into dropping its ban on hormone-treated beef, was greeted with disbelief by the French government and by farmers in the south-western Aveyron region who depend on the industry for their livelihoods.

"Maybe the Bush administration indulged itself by taking this decision just before it leaves," Robert Glandieres, president of the roquefort producers' group, told Reuters.

The tariff on roquefort, condemned as "incomprehensible and inadmissible" by the French government, will probably have a minimal effect, given exports to the US account for just 2% of annual sales. French farmers said it would mean "the end" for roquefort in the US and vowed to take "symbolic actions" in return.