The Treasury says it refused to release sections of documents about flat tax policies because doing so would “prejudice the UK’s international relations” and the government’s ability to formulate tax policy.

In June, someone — a Liberal Democrat advisor, I have reason to believe — filed a Freedom of Information Act request for “any analysis or work that has been done by the Treasury or for the Treasury” on flat taxes.

In response, the Treasury the Government only released those parts of its analysis that supported the Government’s opposition to the flat tax. The original disclosure, reported in the Financial Times, indicated that Treasury officals had ruled out flat taxes. But redacted sections of the documents, obtained by Tory shadow chancellor George Osborne apparently showed that the government was aware of some arguments in favour of flat taxes, were later provided to the Daily Telegraph, which suggested that ministers had to approve such redactions.

This led to some speculation in the blogosphere about which exemptions to the FOIA the Treasury used to justify the exemptions.

And now we know. In the justification for the redactions sent to the original requester and released to me under a seperate Freedom of Information Act last week (albeit three days late), the Treasury outlined why it believes that it was not in the public interest to release some segments of the flat tax analyses. Baljit Phamber of the Treasury’ Correspondence and Enquiry Unit wrote:

We have decided that some information is exempt under section 27 of the FOI Act because disclosure would be likely to prejudice the UK’s relations with another State. The public interest in non-disclosure, because of the likely damage to the UK’s international relations, and becuase it woudl be likely to hamper future discussions on policy issues with the State the information refers to, and others. This would mean that UK policy making on tax was less well informed.

Other information is withheld under section 35(1)(a) of the Act. This exemption applies because the information relates to the formulation and development of government policy concerning tax, whcih involves consideration of other tax regimes. Disclosure would not be in the public interest as it would be likely to prejudice our ability to consider new ideas, explore options that might or might not be adopted as policy in the future. Policy development requires the essential ability to think freely; explore a wide range fo options; in order to contribute to the formulation of government policy. The Treasury has concluded that in this case the public interest in non-disclosure outweighs the public interst to release as teh effect of releasing such information will be detrimental to future policy development on the general tax regime.

That the Treasury cited the controvertial section 35 exemption in this case is not surprising, but the section 27 exemption is. Presumably some of the flat tax documents contained information obtained in confidence from another country’s finance minstry. This may refer to redactions to the discussions of Estonia.

The Permanent Secretary to the Treasury, Nicolas McPherson, denied that any minister had been involved in the decisions involving the FOI request. This was true, because only section 36 of the Act requires a minister to sign a conclusive certificate indicating that it was his opinion that disclosure would “prejudice to the effective conduct of public affairs”. Sections 27 and 35 do not include this requirement.

The Telegraph’s assertion that Gordon Brown (or another minister) was necessarily involved in the redactions is therefore wrong.

One conservative national newspaper columnist whom I spoke to about this story pointed out, however, that civil servants will have been aware of what was politically prejudicial to their minister and will have found a way of preventing disclosure without requiring a minister’s signature.

As Bishop Hill pointed out, the key issue here is why information favouring the government position was released while justifications were found to withold information detrimental to its policy.

Contrary to my hopes, my request for the justifications has raised more questions than answers.