In a robust defence, Mr Garel- Jones blamed 'captious and ill- informed' media reports for damaging confidence in the integrity of government and creating the
'absurd idea' that there was a conspiracy to sell arms to Iraq and pervert the course of justice.
Mr Garel-Jones was one of four ministers to sign public interest immunity certificates seeking to withhold Whitehall documents from the defendants in the case.
Deputising for the Foreign Secretary, he said that he was 'irked' to discover the certificate in his ministerial box at 2am. He had never signed one before and later expressed anger at the short notice he was given to consider it.
He said he did not seek further advice. 'I didn't feel any unease and signed it without hesitation,' he said.
He believed strongly in the principle of confidentiality for advice given by officials to ministers. He took a 'hardline view' that it was 'right and proper' to maintain that confidence. He did not consider whether each individual document, if disclosed, would be against the public interest.
Lord Justice Scott said judges presented with PII certificates assumed that ministers personally believed disclosure would be damaging.
Mr Garel-Jones's certificate warned that 'unquantifiable damage' would result from disclosure. He denied overstating the position. Unquantifiable could mean both large and miniscule damage, he said. Judges were well able to interpret words capable of wide meaning he said, adding: 'Certainly, politicians are.'
He claimed it was media coverage of the Government's role that had caused the real damage to the public interest.
'It has implanted in the minds of ordinary citizens that public servants were engaged in some sort of conspiracy with ministers to see if they could somehow have slipped arms to Iraq when no one was looking, which is absurd.
'When one talks about injury to the public interest, the injury is that I have had to explain to my constituents at some length that the actions I took were proper and I was not seeking to pervert the course of justice to protect the Government from some sort of skulduggery,' he said.