I'm interested if British people actually commented on the propaganda they experienced in their lives. Did it actually impact them or their way of thinking? I would much rather read primary sources such as diaries, letters, and the like, but secondary sources work as well.
Although I can't name any primary sources that deal specifically with Britons reactions to propaganda, I can suggest a number of excellent works by historians that deal with the subject. Most notably:
Nicholas Hiley has also written on propaganda posters, and is worth looking into.
Unlike in Germany, the British government did not conduct a considerable amount of state organized propaganda. Most of it came via private organizations/individuals, such as men like Max Aitken and Lord Northcliffe, and was manifest in manifold forms, mediums, and connotations. Reactions to this propaganda was just as varied as the propaganda itself, but the trend most noticeable seems to be that positive, reinforcing propaganda emphasizing comradeship and working together, tended to gain more support and attention than negative propaganda, ie Women of Britain say Go!, Bash the Hun, etc. Moreover, propaganda tended to be successful when it 'jived' so to speak with public opinion and mood, rather than forcing an opinion or a message done people's throats. [Stephen Badsey gives an excellent lecture here, which touches on some of this] (https://www.youtube.com/watch?v=ziGow3CLalo).