In the House of Commons, members may not accuse one another of lying. A Speaker’s ruling of 1973, citing Erskine May, the guide to parliamentary procedure, listed “charges of deliberate falsehood” as unparliamentary. The ruling added: “Good temper and moderation are the characteristics of parliamentary language.”
The rule produced its own vocabulary. On 22 February 1906, Winston Churchill, then Under-Secretary for the Colonies, was asked whether the government condoned slavery of Chinese laborers in the Transvaal. He replied that the word slavery “in its full sense could not be applied without a risk of terminological inexactitude.” Terminological inexactitude is still used as a polite word for a lie.