The failure to trace the history of infected cattle raises serious questions about government claims that "British beef is safe to eat" and may raise new concerns about easing the ban at the Florence summit on Friday.
Only by establishing where an infected animal was born and bred can veterinary experts identify "at-risk herds", which Britain accepts must be singled out for slaughter to ensure that no suspect beef is consumed. So far about 35,000 herds have been identified as "at risk", partly by tracing the histories of cattle among the 160,000 known to be infected. If the histories of 11,000 have not been traced, commission experts calculated yesterday that statistically a further 2,500 at-risk herds may have so far escaped detection.
The latest evidence of Britain's poor eradication methods emerged at the European Court of Justice in Luxembourg, where Sir Nicholas Lyell, the Attorney-General, yesterday launched Britain's legal challenge to the worldwide ban.
Sir Nicholas argued that the ban was illegal and "wholly wrong". He insisted that the court should suspend the ban immediately, pending a full hearing of the case, because Britain agriculture was suffering "irreparable damage" and the risk to public health had already been entirely removed by eradication efforts. A decision is expected within a few days.
During the hearing, lawyers for the European Commission repeatedly questioned the efficiency of Britain's BSE-eradication plan, which will be on the agenda of heads of government tomorrow in Florence. They argued that Britain's failure to set up adequate cattle tracing systems was one of many causes for continuing fears about the safety of British beef.
James Flett, for the commission, told the 15 judges that 11,000 infected cattle had never been traced back to their "cohort" - or contemporaries in their herd of origin. Mr Flett said it was essential to identify the infected animal's cohort, so that all cattle in the same herd at the same time could be traced. If one animal contracted BSE, believed to be due to eating suspect feed, others in the herd must be deemed "at risk".
The figure of 11,000 untraced cattle, which, according to commission sources was originally given by British officials, was not disputed yesterday by government lawyers.
Although Britain had promised to set up better tracing systems and computerised networks of cattle, past failures gave little ground for reassurance, Mr Flett asserted.
"Suppose I find myself in the British countryside and I see three cows," Leif Sevon, the Finnish judge, asked. "Would it be possible for me to find out which animal might be infected and which is not? Is there such a system in the UK so one can trace the background?"
Sir Nicholas answered: "To a substantial degree yes. But it depends. Some are easier to trace than others. I think to say that every cow can be traced would be going too far."
The broad thrust of the Government's legal challenge to the beef ban centred yesterday on claims that the commission had imposed it as a result of consumer concern and to protect European markets, which Sir Nicholas argued it had no power to do. "A health scare is no basis for the ban," he said.
The Commission argued that it was entirely justified to take into account consumer concerns about public health, to protect the single market. It was "wishful thinking" for Britain to believe that by lifting the ban consumers would regain confidence in beef. Rather, Mr Flett said, there could be a mass consumer boycott of beef.Reuse content