The alarm shown by Justice Secretary Jack Straw at the prospect of 40 convicted murders and terrorists walking free from jail because of a loophole in the law is understandable.
The blow to public confidence in the criminal justice system were such an eventuality to occur would be calamitous.
It is right for Mr Straw to propose emergency legislation in order to acquire parliamentary approval for witnesses to give evidence anonymously in trials where it can be shown that their lives would be in danger if they were forced to appear in open court - even if MPs have to miss part of their summer holiday in order to vote on the matter.
Mr Straw must realise, though, that anonymity for witnesses cuts across a basic tenant of English law - that someone accused of a crime has the right to know the identity of the person accusing him - and as such should only be used in the most extreme circumstances.
It is a reflection on the violent times we live in that anonymous evidence is increasingly permitted by the courts.
Convictions secured in at least 40 murder cases tried in recent years would have been put at risk if Mr Straw had not sought to pass emergency legislation, including those found guilty of murdering Birmingham teenagers Charlene Ellis and Letisha Shakespeare in a drive-by shooting.
The recent ruling by the Law Lords that the use of anonymous witnesses is not permissible has already led to the collapse of one high-profile trial into alleged po-lice corruption and the shooting of an East London businessman. There will have to be a re-trial at considerable expense to the public purse.
Meanwhile, the extent to which we are routinely moving away from open trials is becoming evident.
There are believed to be as many as 600 applications pending for witness anonymity across England and Wales, a total described by a senior figure in the legal profession as staggering.
Suspicion is growing that police, in order to persuade reluctant witnesses to give evidence, are dangling the offer of anonymity when the circumstances do not really warrant such a radical departure from normal processes.
The Home Secretary, Jacqui Smith, has spoken of the need for a system where defendants' rights are protected but the rights of people to take part in a trial are also protected. She is correct, but the Government faces a difficult task to secure the right balance.