John Honey, an educator with a little training in linguistics, published several polemic works against the development of the teaching of English. The Language Trap, a monograph published in 1983, inspired much debate in the English press, as did Does Accent Matter? in 1989. Language is Power: The Story of Standard English and its Enemies was published by Faber and Faber in 1996.
Honey is quite outside the linguistics community. Evidentally he studied under Barbara Strang for some time, but his work has been as a professor of education and as a lecturer in English as a foreign language. As one might expect, his first chapter has him standing in opposition to an "orthodoxy" in the academy, the view that all languages are essentially equal. Honey takes a long time to explain why he thinks Standard English is better than local variants, and for much of the book he lists the views of mainstream linguists as if the reader would easily perceive that they are false. Eventually, he explains that, in his view, Standard English is better because it is used for academic discourse, whereas non-standard languages are not. Well, he never seems to fully consider that standardization is automatically acheived once a given language is used at higher and higher levels of discourse, so that if all teaching to the university levle were done fully in something like AAVE, then a standard language would follow as a matter of course.
Furthermore, Honey opposes making standard languages out of the many tongues around the globe, claiming that it would take too much effort and every one can just use English instead. Well, my apologies, but I'm in this field because I enjoy the (very threatened) "rainbow" of languages, and I would certainly hate to see English used everywhere instead. I imagine most linguists chose linguistics as an occupation for the same reason. So, if one takes "linguistic diversity is good" as axiomatic, then Honey's proposals are rather barbaric, really.
Honey admits that British and American English standard usage are essentially the same, but claims that it would be better for everyone if all English pronunciation grew closer to the Received Pronunciation. One example he gives of the "deficiency" of American English pronunciation is that "they are at it again" and "they are added again" are homophones. In this, he seems to miss two facts that are obvious even to linguistics neophytes. One, all language is ambiguous, that's why there's so much redundancy built in for context, and two, even the Received Pronunciation has its fair share of homophones, e.g. "formerly" and "formally".
As for the theme brought up in the title, Honey claims that since Standard English is the language of power, by not educating young people in Standard English, teachers are denying them access to that power. However, Honey never makes the case well enough that it really is like this, for one could equally argue that fracturing English would remove power from one variant and promote local variants to higher status.
Honey's misunderstandings of linguistics are risible, though no doubt he'd attack me as a servant of a misguided "orthodoxy". I can't much recommend the book, unless you are interested in the polemics surrounding Standard English which flare up now and again in England and the United States.