In December 1955, Butler was moved to the post of Lord Privy Seal and Leader of the House of Commons. Although he continued to act as a deputy for Eden on a number of occasions, he was not officially recognised as such, and his successor as Chancellor, Harold Macmillan, insisted on an assurance from Eden that Butler was not senior to him. Harry Crookshank warned him that he was committing "sheer political suicide" by giving up a big department. He recorded that after December 1955, "it was never again said of me, or for that matter of the British economy either, that we had "la puissance d'une idée en marche"".