 In October 1963 , just before the Conservative party 's annual conference , Macmillan was taken ill with a prostatic obstruction . The condition was at first thought more serious than it turned out to be , and he announced that he would resign as Prime Minister as soon as a successor was appointed . Three senior politicians were considered likely successors , Butler ( First Secretary of State ) , Reginald Maudling ( Chancellor of the Exchequer ) and Lord Hailsham ( Lord President of the Council and Leader of the House of Lords ) . The Times summed up their support : 
