 The Mutual Defence Agreement followed on 3 July 1958, speeding up British ballistic missile development, notwithstanding unease expressed at the time about the impetus co-operation might give to atomic proliferation by arousing the jealousy of France and other allies.Macmillan led the Conservatives to victory in the 1959 general election, increasing his party's majority from 60 to 100 seats.The campaign was based on the economic improvements achieved as well as the low unemployment and improving standard of living; the slogan "Life's Better Under the Conservatives" was matched by Macmillan's own remark, "indeed let us be frank about it—most of our people have never had it so good," usually paraphrased as "You've never had it so good."