THE principle of "innocent until proven guilty" is the cornerstone of our system of justice and must be preserved at all costs.

It will face its sternest test in December when, as a matter of course, juries will be told of defendants' previous convictions.

Such a reform will undoubtedly make it easier to achieve convictions. But it will not extend the notion of fairness by which the effectiveness of our courts should be judged.

At present innocence is presumed, and juries examine each case on its merits.

It will be much more difficult for juries to presume innocence and look at cases objectively when previous convictions are disclosed.

It is hard to see how such information will not be prejudicial.

The frustration of the police and the Crown Prosecution Service at the existing restraints is understandable.

However, it is imperative that the onus on the police and prosecution lawyers is to provide sufficient evidence on which to achieve a conviction.

With previous convictions as an important part of evidence, it may be tempting to compile a less than thorough case.

A great deal of excellent work is done by police officers and the prosecution service to bring the guilty to justice. But too often these endeavours are overshadowed by miscarriages of justice.

There is a grave danger that the disclosure of previous convictions will lead to even more miscarriages of justice.

It is vital for the reputation of our system of justice that the burden of proving guilt beyond all reasonable doubt remains onerous.