A witness of the calibre of Lord Gill, the Lord President of the Court of Session, cannot be dismissed lightly, particularly when the subject is a change to a fundamental rule of Scots Law that has been in place for centuries.

"Listen to the wisdom of ages," said Lord Gill yesterday. "It has a lot to tell us."

The Scottish Government seems not to be listening and appears determined to press ahead with its plans to scrap the rule that requires corroboration in criminal cases. The rule means evidence against an accused has to come from two sources and Lord Gill not only believes it is one of the finest features of our justice system, he thinks scrapping it could have a detrimental effect on criminal cases.

His first area of concern is that removing corroboration could result in fewer convictions - a serious problem if true because the point of Justice Secretary Kenny MacAskill's plans is to improve the conviction rate. Quite rightly, the Scottish Government and the Crown Office are worried about the conviction rate for sexual offences - the rate for rape, at around 7% of reported cases, is particularly appalling - and they believe the requirement to find evidence to support the word of the victim is getting in the way.

This is probably true, but that does not mean the requirement is a bad one. As Lord Gill told MSPs yesterday, the risk in a trial without the need for corroboration is that a defence lawyer would simply ask the jury whether it was fair to convict an accused person on the word of the accuser with nothing else to support it. On the face of it, a jury would be likely to answer no to such a question and acquit the accused, thereby reducing the conviction rate overall.

Of course, any case would still have to meet the standard of beyond reasonable doubt, but the Faculty of Advocates has also already warned that convictions may be less likely because police officers will focus less on finding corroborative evidence, thereby weakening the overall case that goes before the jury.

Lord Gill's second concern centres on the chance of more miscarriages of justice. He believes that of the convictions that were achieved, more would be likely to be wrongful - a position also taken by the Law Society of Scotland. According to the society, trials could end up being no more than a contest between two competing statements, meaning juries would be more likely to get it wrong.

Naturally, one cannot just take the word of lawyers on this, but equally Mr MacAskill must take note of the evidence building against his proposal. This newspaper has always said the corroboration rule should not be discarded lightly and now, with the exception of Lord Carloway, who recommended abolishing it in the first place, not a single judge can be found to support the change. Yes, it would probably make it easier to prosecute offences of domestic abuse and rape but the justice system is not just about securing convictions. It is also about protecting against the risk of innocent people going to jail and if scrapping the corroboration rule threatens that, it must be allowed to stay.