According to recently disclosed Whitehall documents seen by The Independent, the official defiance lasted for more than 10 years, and is explained by the fact that although ministers reached a decision, they did not "promulgate" it with "immediate directives".
The disclosure suggests that although ministers might assume that if they reach an official decision, it will be carried out by their officials, in this case civil servants used the lack of an order to procrastinate.
Official Ministry of Defence papers, released to the Campaign for Freedom of Information, also reveal that the initial decision to abandon the offensive capability had nothing to do with an enthusiasm for disarmament, or even repugnance for the form of warfare - but economic cost.
The papers set down the guidelines under which Whitehall files are to be withheld from public inspection - even after the basic 30-year secrecy rule that covers most such documents.
The "sensitivities" that will ensure retention include a number of general categories - including files covering "reports on UK or UK-sponsored or directed Chemical Warfare or Bacteriological Warfare (CW/BW) trials involving the unwitting exposure of populations".
As the papers cover categories of material to be withheld, no examples are provided, but that category suggests that such trials were carried out on "unwitting" populations.
However, the most open exposure of what lay behind the "sensitivities" of Whitehall was the section relating to the 1956 Cabinet committee decision to abandon offensive chemical and bacteriological capabilities. As an example of material with "potential international sensitivity", the guidelines cite: "Any papers which suggest that offensive capabilities continued beyond the mid-50s.
"For various reasons, there was no sharp cut-off of offensive-related activity following the mid-1950s Cabinet Defence Committee decision to abandon offensive capabilities in CW/BW. Consequently, occasional papers of the late 1950s and early 1960s may reflect what could be interpreted as a continuing offensive policy by Her Majesty's government."
The guidelines provide the example of an agreement to make between 200 and 400 tons of nerve agents VX or GE.
It then adds: "It should be noted that the 1956 Cabinet committee decision was not promulgated by immediate directives and was implemented over more than a decade. Papers in this category may be particularly sensitive if they appear to reflect ... [Ministry of Supply, War Department, and later Ministry of Defence] reluctance to follow Cabinet committee decisions.
"Also, such papers often reveal that the motivation for UK abandonment was economic rather than the unilateral enthusiasm for arms control that has been emphasised in recent years."
Maurice Frankel, director of the Campaign for Freedom of Information, said yesterday: "What these guidelines show is that most of the areas described as `sensitive' are not sensitive at all; they are embarrassing." Whitehall files should not be withheld from public inspection after 30 years on that basis. But Mr Frankel said: "At least it is a positive step that they are willing to release the guidelines."