Napoleon tries to “clarify” things to the human farmers from the surrounding area at a peacemaking dinner the pigs hold. Orwell uses situational irony to highlight the duplicity in Napoleon's toast, as the narrator recounts it:

For a long time there had been rumours—circulated, he had reason to think, by some malignant enemy—that there was something subversive and even revolutionary in the outlook of himself and his colleagues. [...] Nothing could be further from the truth! Their sole wish, now and in the past, was to live at peace and in normal business relations with their neighbours. This farm which he had the honour to control, he added, was a co-operative enterprise. The title-deeds, which were in his own possession, were owned by the pigs jointly.

Napoleon’s speech here is full of both verbal and situational irony as he (through the third-person reporting of the narrator) addresses the human farmers. Even though Napoleon was the figurehead of the animal revolution, in this moment he is claiming that rumors of subversive or revolutionary behavior by the pigs are unfounded. His assertion that "nothing could be further from the truth" is therefore verbally ironic (we know he doesn’t mean what he is saying, and, indeed, it’s the opposite of the truth) and situationally ironic; a reader would not expect the leader of the revolution to deny it happened. This statement is ironic because everyone present—Napoleon, the other pigs, the human farmers—know the truth of the pigs' revolutionary past. However, as it is more convenient to forget these facts, the pigs and the humans mutually agree to accept this false version of history. The use of verbal and situational irony here critiques the corruption that now characterizes the pigs’ leadership. It also highlights the ease with which selfish leaders can cast aside selfless ideals when there’s power to be won.