asked Her Majesty's Government:
Whether, when it is proposed to commit the United Kingdom to direct participation in any war, international armed conflict or international peace-keeping activity, they will publish the opinion of the law officers of the Crown as to the legality of the proposed use of force by the armed forces.
Advice from the law officers is covered by legal professional privilege and is subject to a longstanding convention that prevents disclosure of the advice—or even the fact that the law officers have been consulted—outside Government. The Government consider it important for Parliament and the public to be given a proper explanation of the legal basis on which key decisions, such as a decision to use force against another state, are taken.
This is what happened in relation to Iraq in 2003. While there is a particular need for certainty and clarity in relation to military action, the public interest would not necessarily be served by publication of the legal advice itself, which may refer to secret intelligence or military plans and could include references to the arguments both for and against what is proposed. It would be for the Prime Minister of the day to determine how best fully to explain the legal basis for action to Parliament, including whether that could be done by disclosing the legal advice received in that respect.