The Attorney General's decision to block public disclosure of letters the Prince of Wales wrote to Government ministers was upheld by the High Court today.
Guardian newspaper journalist Rob Evans accused Dominic Grieve of going wrong in law and "overriding an independent and impartial tribunal".
But today the Lord Chief Justice, Lord Judge, sitting with Lord Justice Davis and Mr Justice Globe, refused to overturn Mr Grieve's veto last October on the release of correspondence between Charles and seven Government departments.
They ruled that it was "an exceptional case meriting use of the ministerial veto to prevent disclosure and to safeguard the public interest".
Mr Grieve, the Government's principal legal adviser, said his decision was based on his view that the correspondence was undertaken as part of the Prince's "preparation for becoming king".
Making the letters public could potentially damage the principle of the heir to the throne being politically neutral, and so undermine his ability to fulfil his duties when king, said Mr Grieve.