Powell had supported British membership of the EEC in 1961, when then Conservative Prime Minister, Harold Macmillan, applied unsuccessfully for Britain to join, as Powell believed it to be a way to make Britain liberalise its economy. However, Powell changed his mind soon after when investigating the EEC's origins and methods in greater detail, and believed that Britain joining the EEC would extinguish Britain's ability to be a self-governing nation. Powell claimed that the question of British membership of the EEC "must be the question which subtends all others...for – in peace as in war, it is the great, the ultimate, question for any nation". "Independence, the freedom of a self-governing nation", Powell argued, "is in my estimation the highest political good, for which any disadvantage, if need be, and any sacrifice, are a cheap price".