A civil liberties storm erupted yesterday after a senior judge called for the genetic details of every person in Britain, and all visitors to the country, to be added to the national DNA database.
Critics warned that the "chilling" move would infringe privacy, be hugely impractical and have only a marginal impact on crime.
Downing Street and the Home Office, which have been accused of moving Britain towards a surveillance society, distanced themselves from Lord Justice Sedley's controversial suggestion without entirely ruling it out.
About 4.1 million samples are already on the database, almost 7 per cent of the population and far more than in any other Western country. Police can take DNA from anyone arrested, regardless of whether they are eventually charged.
But Sir Stephen Sedley, one of the most experienced Court of Appeal judges, protested that there were "indefensible" anomalies in the system, including disproportionate numbers of people from ethnic minorities on the database.
He said: "We have a situation where if you happen to have been in the hands of the police, your DNA is permanently on record and if you haven't, it isn't."
The judge told the BBC that the remedy could be to place every person on the database, as well as the 32 million annual foreign visitors to the country, for the "absolutely rigorously restricted purpose of crime detection and prevention".
He acknowledged that the creation of a universal database had very serious implications, but argued that it ultimately led to a fairer system.
Tony Blair said last year that he could see no reason why the DNA of everyone should not ultimately be kept on record.
Gordon Brown's official spokesman said the Government had no plans to introduce a compulsory database, and stressed the logistical and bureaucratic problems, and the civil liberties concerns, surrounding such a move.
Tony McNulty, the Home Office minister, said he was broadly sympathetic to the "real logic" of the judge's argument. But he stressed: "There is no government plan to go to a compulsory database now or in the foreseeable future."
Nick Clegg, the Liberal Democrat home affairs spokesman, accused the Government of a "cloak-and-dagger strategy of creating a universal database behind the backs of the British people".
David Davis, the shadow Home Secretary, called for a parliamentary debate on the issue. He said: "The erratic nature of this database means that some criminals have escaped having their DNA recorded whilst a third of those people on the database – over a million people – have never been convicted of a crime."
Shami Chakrabarti, director of the human rights organisation Liberty, said a database of DNA from convicted sexual and violent offenders was a "perfectly sensible crime-fighting measure".
But she added: "A database of every man, woman and child in the country is a chilling proposal, ripe for indignity, error and abuse."
The DNA database, created in 1995, is growing by 30,000 samples a month. It contains the profiles of 884,000 children, including more than 100 who are less than 10 years old.
The Home Office is currently reviewing the Police and Criminal Evidence Act 1984, which sets out the powers to take and retain biometric data. It will consider whether records should only be held temporarily for minor offenders and people who are not charged.
The Home Office said last night that the database provides police with an average of 3,500 matches each month.