The endeavours of the Disraeli government in Africa, India, Afghanistan and Europe, which were only partially successful and often accompanied by early, humiliating defeats, gave a good deal of fodder to Gladstone for his attacks.
Further, Disraeli's favoured dealing with the Turks, who were responsible for horrendous atrocities against Balkan Christians also laid him open to religious attacks, especially in Gladstone's pamphlet “The Bulgarian Horrors and the Question of the East” (1876).
William Gladstone, appealing to moralistic evangelicals, led the attack on the foreign policy of Benjamin Disraeli (now known as Lord Beaconsfield) as immoral.
[3] Historian Paul Smith paraphrases the rhetorical tone which focused on attacking "Beaconsfieldism" (in Smith's words) as a:Sinister system of policy, which not merely involved the country in immoral, vainglorious and expensive external adventures, inimical to peace and to the rights of small peoples, but aimed at nothing less than the subversion of parliamentary government in favour of some simulacrum of the oriental despotism its creator was alleged to admire.
Besides their trouble with foreign policy issues, it was even more important that the Conservatives were unable to effectively defend their economic record on the home front.