As the article points out, "Conventional wisdom was that accents would disappear and merge into a national way of speaking, albeit with some class and regional variations". But this is coming with a cost as "while big-city accents are surviving and even colonising surrounding areas, the nuances between districts within those cities are disappearing".
The article draws on expert opinion too: the eminent linguist Paul Kerswill of Lancaster University as well as Dominic Watt, a lecturer in forensic speech science of York University and Clive Upton at Leeds University.
So why is this happening? Well, it appears that while local accents are dying out, the strong regional accents seem to be spreading out from their traditional bases and into new territory. In a way it's like a localised form of dialect levelling and it's happening for many of the same reasons: movement of people, prestige and status in society and the power of the media. Certain regional accents appear to have gained a foothold in modern Britain as signifiers of authenticity and honesty, and perhaps a marker of working class tradition, and have therefore maintained their strength against what was ( a few years ago at least) thought to be the all-conquering power of London and Estuary English.
The article goes on to add some other interesting points:
Accents are more varied in northern England because they have not been subjected to the mass levelling of speech caused by London and its commuting hinterland. In the southeast, Kent, Essex and East and West Sussex are all losing their distinctive accents while the capital’s own cockney is also under threat.I'd definitely recommended having a look at the whole article and following up some of the wider issues about language, region and identity for your work on ENGA3. And I'd also recommend a look at the Kerboodle video clips for this unit where Kevin Watson of Lancaster University gives an excellent introduction to the main ideas concerned with the study of accent and dialect.
(edited on 21.04.16 to remove salacious references and rather eye-popping picture)