SCOTLAND’S most senior judge has been accused of stifling a Holyrood inquiry into the country’s prosecution service.

The Lord President, Lord Carloway, has written to every level of the judiciary telling them he has refused to give evidence to the Justice Committee’s explosive probe into the Crown Office and Procurator Fiscal Service (COPFS).

His reasons were laid out last week to every high court judge, the Sheriffs’ Association and the Scottish Justices Association (SJA), which represents Justices of the Peace.

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He said the Scottish Courts service as an institution should give evidence to the committee, rather than individual members of the judiciary, even retired ones.

After the intervention, the SJA pulled out of its scheduled appearance at today’s committee.

It was to have been represented by vice chair Tom Finnigan, a JP in North Strathclyde.

Two JPs acting in an individual capacity will now attend instead.

The behind-the-scenes activity is understood to have troubled the committee’s convener, Conservative MSP Margaret Mitchell, who at the weekend told a meeting of JPs she would be concerned if there was a perception that freedom of speech was being restricted.

Opposition parties are also privately uneasy about a possible 'chilling effect'.

A Labour source said: "It's important that no one in a position of authority attempts to stifle this inquiry."

The Lord President’s office refused to release the message sent to the judiciary.

However the Justice Committee last night published the refusal letter from his private office, which set out his thinking.

It said Lord Carloway felt it would not be “constitutionally appropriate for a serving judge or sheriff to meet with members of the committee” informally.

It said the same applied to any retired judge or sheriff still available for re-employment.

Despite judges and sheriffs seeing the work of prosecutors on a daily basis, and often criticising the Crown’s actions from the bench, Lord Carloway claimed they were not in a position “to comment on various issues, given that such comments would be based either on anecdote or an incomplete understandings of the facts”.

He also claimed judges, “given their subjective experience of a limited pool of cases”, were “not well placed” to offer views on the experience of victims or witnesses.

Lord Carloway has previously given evidence to the committee on other matters, as have two previous Lords President, Lord Hamilton and Lord Gill.

The COPFS inquiry has heard repeated evidence of prosecutors, although dedicated and professional, being under-resourced and overwhelmed by their workload.

The Scottish Police Federation said this resulted in courts being jammed with cases, officers’ time being wasted, and victims of crime being let down.

Tory justice spokesman Douglas Ross said: "It seems astounding that judges or sheriffs wouldn't be in a position to give evidence on the Crown Office.

"They are watching it in action every day and seem like they would be ideally placed to speak to the Justice Committee on what needs to be improved."

A Labour spokesman said: “Scottish Parliament committees do vital work to scrutinise the government and public bodies on behalf of Scottish voters.

"Witness evidence is a crucial part of that and it would be concerning if anyone feels they are under pressure not to appear before MSPs.”

John Finnie MSP, Justice spokesperson for the Scottish Greens, said: “The Lord President fulfils a vital public role and he has a valuable insight into the workings of the Crown Office & Procurator Fiscal Service. His appearance at the Justice Committee would be appreciated so that we can make informed decisions about the functioning of this service.”

Lord Carloway, 62, was appointed Lord President last December. His salary is £222,862.

As part of his duties, he chairs the board of the Scottish Courts and Tribunals Service.

James Wolffe QC, then Dean of the Faculty of Advocates and now the Lord Advocate, the head of the COPFS, welcomed his appointment at the time as “richly merited”, adding: “I look forward very much indeed to working with him.”

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The Judicial Office for Scotland said: “The Lord President’s Private Office wrote to all Senators [judges], the Sheriffs’ Association and the Scottish Justices Association, outlining the Lord President’s reasons for declining the invitation to give evidence to the Justice Committee’s inquiry into the role and purpose of the Crown Office and Procurator Fiscal Service.

“It was made clear that if members of the SJA wished to attend to give oral evidence, that was a matter for them, and the Lord President offered no view in that regard.

“The Lord President’s position is that the Scottish Courts and Tribunals Service is better placed to provide an informed submission to the inquiry.”