France is breaking European Union law by banning British beef over fears of mad cow disease, the EU's highest court said on Thursday.
The final ruling from the European Court of Justice puts new pressure on Paris to drop its unilateral ban or face the prospect of hefty fines.
"The court declares unlawful France's refusal to lift the ban on correctly marked or labelled imports of British beef and veal from 30 December 1999," the court said in a statement.
In a legal twist, it found that the EU rules governing the resumption of British beef exports were "unclear" and the panel of 13 judges therefore ordered both France and the European Commission to shoulder the costs of the case.
The court also stressed the importance of a reliable tracing system for meat to protect public health.
The ruling by the court is final and cannot be appealed, meaning that French Prime Minister Lionel Jospin's government will now have to choose whether to end the ban or face the prospect of more legal action that could result in huge fines.
French farm minister Jean Glavany was circumspect over the court's verdict, saying he first wanted to study it with Jospin. Sources close to Glavany said a full cabinet debate on the ruling was needed before a decision could be taken.
Jospin was due on Thursday to chair a regular ministerial meeting at his Paris office.
The European Union banned British beef exports in 1996 after Britain linked mad cow disease, widespread in the country, to Creutzfeldt-Jakob disease which has so far killed about 100 people, mostly in the UK but also in France.
After Britain acted to control mad cow disease, bovine spongiform encephalopathy (BSE), the European Commission rescinded the ban in 1999.
France refused to comply, citing health concerns, and the Commission sued the country to force it to respect EU law.
EU health commissioner David Byrne welcomed the court's ruling and said he expected France to implement it.
"The decision vindicates the Commission's policies and stance. I expect France to implement the judgment and lift the ban on the import of British beef," he said in a statement.
Britain's main farm union, the NFU, kept up the pressure on Paris following the ruling, saying France had damaged "the very credibility of the European Union" and should face stiff fines as a result.
"It is vital that the Commission takes a tough line over this flagrant and lengthy breach of EC law," National Farmers' Union (NFU) president Ben Gill said in a statement.
If Paris were to defy the court -- a distinct possibility given French farmers' political clout and the approaching presidential elections -- the Commission could ask the judges to fine France for breaking the law.
The power to impose fines is considered the ultimate sanction for the Commission. It can only be invoked after the European Court of Justice has already ruled once against the country after a lengthy hearing.
Only one of the EU's 15 member states has been fined in this way to date. Greece was subjected to a daily penalty of 20,000 euros ($17,950) last year after the court ruled that it was ignoring EU environmental laws.
The Commission stopped fining Greece last July but not before it had collected 5.4 million euros from Athens.