It’s not at the top of the list, but a fresh reason to resent Boris Johnson surfaced last week in the course of a news story about old cases of child abuse. Last year the prime minister averred that the pursuit of these cases, from the 1970s and 80s and many involving state institutions, was akin to “spaffing” money up the wall. Last week Labour called on him to apologise for the remark after the publication of new police figures indicating the abuse had been more widespread than assumed. The scandal is Johnson’s attitude, of course, but it might be observed as a side note that the word “spaffing”, which was funny for five minutes, has now been categorically ruled out for usage.

His style works to promote him as removed from the masses while buying him licence to chuck out ‘spaff' at the other end

Johnson is very proud of his linguistic style, which falls into a familiar category. It is his charm, and the charm of English men of his class more broadly, to marry lavish displays of education with the kind of demotic outbursts that signal one is simply too confident – too overburdened with options – to care where one’s register lands. During a UN speech last year, Johnson retold the story of Prometheus – in itself a piece of ostentatious irrelevance, rendered more so by Johnson through his choice of detail. The fact that he managed to get the line “tube of fennel” into his precis felt like an undergraduate fulfilling a dare by a friend.

Relative to other politicians, the unusual part of this style of Johnson’s is that it works to promote him simultaneously as removed from the masses, via his ease with classical allusion, while buying him licence to chuck out “spaff” at the other end. For most politicians the range is narrower and characterised more by anxiety. In the 90s, Bill Clinton’s wild stab at the word “diss” to describe his wife’s general attitude towards him effectively killed the term overnight and rendered him ludicrous. George W Bush, addressing Tony Blair at a G8 summit as “Yo! Blair,” killed everyone briefly. (Blair, not to be outdone on this score, parried the president’s casualness with a swift and deadly reference to “this trade thingy”.)

Of course the language used by Tony “I’ve not got a reverse gear” Blair has been the subject of endless analysis and speculation, mainly as to how much he was depressing his middle-class instincts with his array of man-of-the-people expressions. When Johnson “talks down”, it’s a louche gesture that seems designed less to promote him as one of us than to reinforce the idea that by ranging the spectrum, he is very much above it. With Blair, it always felt overworked, the linguistic equivalent of Peter Mannion, Roger Allam’s character in The Thick of It, being told to untuck his shirt to appeal to young voters.

Johnson, one assumes, doesn’t have to be told to untuck his shirt, his state of curated dishevelment many decades in at this point. Like everything else about him, his language betrays a man nakedly charmed by himself. When I see him smirk and speechify, or flip between references to Greek poetry and the word spaff, I’m reminded of Pierre, the tiny morality play by Maurice Sendak in which a precocious child shouts “I don’t care” at everything that comes his way – good, bad or indifferent – until he is mercifully eaten by a lion.

• Emma Brockes is a Guardian columnist