The Scottish Government is failing to act in the “spirit” of Freedom of Information laws, an architect of the legislation has claimed, as it was revealed scores of requests are regularly sent to special advisers and ministers for approval.

A snapshot of requests over a two week period in March shows that out of 141 requests for information, 57 of them were referred to politically appointed advisers and 39 were sent for “ministerial approval”.

The figures have prompted criticism from Lord Wallace, one of the legal minds behind Scotland’s transparency laws, who claimed the referrals could create a culture of secrecy within the government.

He said: “Whilst such a systematic involvement of Special Advisers wouldn’t be against the letter of the law, it certainly flies in the face of the intended spirit of the legislation.

“I regularly said that the Act would only take us so far. What was needed – and what I hoped the Act would promote - was a change of culture, so the default position would be openness rather than secrecy.

“These apparent practices are far more likely to institutionalise a culture that is anything but transparent.”

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Carole Ewart, convenor of the Campaign for Freedom of Information in Scotland, added that the original act “does not permit information to be skewed or withheld to avoid political embarrassment”.

She said: “The role of advisers is to help politicians manage any fallout from information disclosures not in any way influence what information or what slant on information is released.

“People have the right to receive information under Scotland’s access to information laws, and providing that information is a duty which should be delivered by civil servants who are impartial.

“The involvement of special advisers in finalising the content of so many freedom of information requests is worrying and it is right the public should know the nature and extent of that involvement.”

The new revelations are the latest in a string of controversies around the government’s approach to FOI and the influence of political figures.

In February it was revealed that John Swinney personally intervened in an FOI request, with the release of several documents seemingly blocked at the Deputy First Minister’s request.

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Last year journalists from across the Scottish media signed an unprecedented open letter criticising the government’s approach to FOI. MSPs subsequently condemned the government’s conduct in a unanimous vote in parliament.

This has led to a high-level investigation by the Scottish Information Commissioner which is still ongoing. The findings are due to be published at the end of this month.

Responding to the latest figures, Scottish Labour’s Neil Findlay MSP - who has campaigned for greater transparency - said: “This is a deeply troubling revelation.

“It is now clear that SNP government special advisers – and even ministers themselves – are interfering with Freedom of Information requests on a seemingly industrial scale. That is unacceptable and an affront to democratic process.

“These findings must form an essential part of the Scottish Information Commissioner’s review into the FOI system, which is clearly now more essential than ever.”

A Scottish Government spokesman said: “When preparing FOI responses, officials consider carefully, on a case-by-case basis, whether input or clearance is required from relevant parts of the organisation, including other officials, special advisers and ministers.

“The legal duty to comply with FOI legislation lies with Scottish Ministers, and Ministers are accountable for all FOI responses issued by the Scottish Government.

“It is therefore entirely appropriate that a decision is taken on which FOIs require their clearance, so Ministers are content with proposed information releases or exemptions applied in line with the FOI Act.”