PRESSURE is mounting on the Scottish Government to drop plans to overturn the centuries-old legal principle of corroboration after High Court judges and solicitors across Scotland universally rejected the proposal amid fears it could lead to miscarriages of justice.

In a major review of Scots criminal law last year, judge Lord Carloway said the rule, which ensures all key evidence is backed by two sources, was archaic and had no place in a modern legal system.

But now three major arms of the legal establishment have come out to oppose the move, with the Senators of the College of Justice – which represents every judge in the country – unanimously objecting to the shift, partly on the grounds it would lead to "decreasing confidence in the legal system" and lower conviction rates.

The Law Society of Scotland, which represents some 10,500 solicitors, has also denounced the move to rid the system of the "fundamental safeguard". It followed the Faculty of Advocates lodging its opposition earlier this week.

The Senators of Justice said: "In our view, it is often difficult to assess the true facts on the basis only of the evidence of one witness. A witness may be credible and plausible, yet not be telling the truth (or the whole truth).

"The Scottish courts have on many occasions been grateful for the requirement of corroboration, which in our view provides a major safeguard against miscarriages of justice."

They added: "One particularly anxious area is that of alleged sexual offences, where (without corroboration) the issue becomes one of the complainer's word against the accused's. Our concern is that the abolition of corroboration may result in miscarriages of justice."

Lord Advocate Frank Mulholland has said removing corroboration could lead to an increase in convictions for sexual offences and domestic violence cases.

The judges, who have supported the majority of the Carloway Review, said there was concern about the impact on the quality of police work should the requirement for corroborating evidence be removed.

The response said: "We are also concerned the abolition of corroboration may result in less diligent police investigation pre-trial: knowing corroboration is not required, there may be a relaxation in the search for supporting evidence (even though such may well exist).

"The current perception may be that the conviction rate in certain types of crime (for example, sexual offences) is low. It is our considered view that if corroboration were to be abolished, it would lead to decreasing confidence in the legal system, and to lower rates of conviction generally."

Justice Secretary Kenny MacAskill said he would try to find the best way to achieve the abolition of corroboration after accepting Lord Carloway's study and was "not minded" to reconsider the recommendation or to refer the issue to a Royal Commission.

Professor James Chalmers, Regius Chair of Law at the University of Glasgow and editor of the Edinburgh Law Review, said it was "striking" that judges had taken the unanimous position. He added: "Lord Carloway will be disappointed that his argument for the abolition of corroboration has not persuaded any of the other 33 High Court judges.

"The Scottish Government has already announced its Criminal Justice Bill will abolish corroboration. But it is difficult to see how the Government can favour the view of one judge over the unanimous opinion of the other 33."

The Law Society of Scotland has called for an independent review of Scottish criminal justice, given its concerns.

The society questioned the independence of research carried out for Lord Carloway using Crown Office and Procurator Fiscal Service (COPFS) data and procurator fiscal judgments over the prospects of convictions without corroboration, both of which supported the abolition of the principle.

Alan McCreadie, the society's deputy director of law reform, described the research as "neither independent nor compelling".

He added: "No evidence to demonstrate that the abolition of corroboration will not result in miscarriages of justice has been produced.

"In the absence of such evidence, the society believes that the abolition of the requirement for corroboration without other safeguards will result in a contest between two competing statements on oath and therefore have the potential to result in miscarriages of justice."

A Scottish Government spokesman said: "Lord Carloway's recommendations have been subject to a Government consultation exercise.

"The consultation specifically sought views on whether any additional safeguards would be required as a result of removing the corroboration rule and we will consider all responses."