The BBC sent Freedom of Information requests to all 28 councils which had noauthorisation prior to 2012 to find out how many potentially-unlawful tickets were issued.
Labour backbencher David Winnick urged Mr Cameron to guarantee that no military action would be taken against Libya without "direct authorisation" from the United Nations Security Council.
The allied intervention in northern Iraq in 1991 to save the Kurds, and the imposition of a no-fly zone in southern Iraq to save the Shia Muslims there, were undertaken without explicit authorisation by a Security Council resolution, but were also widely accepted as legitimate.