Massacre of the Innocents
(The), in parliamentary phraseology, means the withdrawal at the close of a session of the bills which time has not rendered it possible to consider and pass. The phrase was so used in The Times, 1859.
“If the secretarial M.P. is to be condemned for ... voting against the Miner's Eight Hours Bill, he is equally censurable if he ... does not support the numerous ... reforms which get the sanction of the Congress during the Massacre of the Innocents at the close of the sitting.” —Nineteenth Century, October, 1892, p. 619.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894