The accent described here is the present-day version of the accent that has been used as the standard in phoneticians' description of the pronunciation of British English for centuries. The definition of this accent is a matter of heated debate and frequent controversy: the arguments will not be rehearsed here, but the interested reader is recommended to look at Jones (1917 and subsequent) and Wells (2000). The most important aspects of this accent should, however, be made clear.
a. The number of native speakers of this accent who originate in Ireland, Scotland and Wales is very small and probably diminishing, and it is therefore a misnomer to call it an accent of BRITISH English. It is an accent spoken by some English people.
b. The great majority of native speakers of this accent are of middle-class or upper-class origin, educated at private schools and (if of appropriate age) university. This does not mean that the accent cannot be acquired by others: the present author (who attended a state school in the Midlands) originally spoke with an accent with noticeable regional features, but has over many years of teaching the phonetics of English acquired an accent not far from the standard one described here.
c. The majority of speakers of this accent live in, or originate from, the south-east of England.
d. The accent is most familiar as that used by most ‘official’ BBC speakers of English origin (newsreaders and announcers on Radio 4 and Radio 3, and most television channels). It is also frequently heard on the BBC World Service, though that service appears to have adopted the policy of sometimes using newsreaders and announcers with noticeable foreign accents. It is clear that this accent will eventually lose its pre-eminent status in broadcasting as a result of the wish to broaden the social base of broadcast speech, but it will take a long time for this to happen.