The Lord Advocate last night won the backing of one of Scotland's most distinguished retired judges.

Former solicitor general Lord McCluskey said he believed Lord Hamilton had no grounds to accuse Elish Angiolini of threatening the independence of the judiciary.

"He's quite wrong," Lord McCluskey said. "What he fails to see is that it is sometimes essential for a minister to comment upon a case. It happens all the time in parliament. He may be asked a question. He may be required by circumstances to make a statement.

"I don't have any objection to people from outside the executive and parliament criticising judges."

Ministers, Lord McCluskey said, were entitled to debate the merits of any decision, just not to comment on the merits of any judge. "He can't say the judge is foolish or the judge doesn't know his rear from his elbow.

"There is everything wrong with a minister saying a judge is a fool or biased, in implying prejudice.

"But if you are to criticise a judgment, there is nothing to stop you doing that, not least in learned articles."

Like most judges, Lord McCluskey is no stranger to criticism of his decisions - either from the public or fellow lawyers. And like most judges, he didn't always like it. "I sometimes felt aggrieved," he said, "that someone had differed from my own point of view, that's a natural human response." Public criticism of judgments is an everyday occurrence, he said. "It is quite common, for example, for people to complain that a judge is too lenient in sentencing."

Lord McCluskey would welcome a public debate on one element of the World's End trial. Charges against Angus Sinclair were dismissed because Lord Clarke felt there was "no case to answer" - not enough evidence to put before a jury. He could not have done so before 1980. That was when the provision was brought into Scots law, an "alien import," said Lord McCluskey, from England.

Lord McCluskey believes the rule of corroboration in Scots law means there is no need for the English-style notion of insufficient evidence.