The conflict of loyalty, of loyalty to my right hon. Friend the Prime Minister—and, after all, in two decades together that instinct of loyalty is still very real—and of loyalty to what I perceive to be the true interests of the nation, has become all too great. I no longer believe it possible to resolve that conflict from within this Government. That is why I have resigned. In doing so, I have done what I believe to be right for my party and my country. The time has come for others to consider their own response to the tragic conflict of loyalties with which I have myself wrestled for perhaps too long.

Hansard, House of Commons, 6th series, vol. 180 col. 465.