Linguists have identified the spread of "Occupational English", which is classless and devoid of regional accent and vocabulary, breaking down traditional speech patterns.
Researchers from the University of Sheffield have found that this new accent of the workplace is quite distinct and more downmarket from received pronunciation.
At the vanguard of the advance of Occupational English are local radio presenters, who shun the clipped tones of the BBC, but speak with a similar accent and vocabulary throughout the country.
At the same time, large parts of northern England and Scotland are now adopting the speech mannerisms of the south-east at the expense of their own regional accents.
John Wells, a professor of phonetics at University College London, said people in Manchester, Leeds and even Glasgow were speaking more like Londoners.
Glottal stops (as in "daw-er" for daughter and "war-er" for water) and the vocalisation of the L ("miwk" instead of milk) are increasingly common in Northern conversation.
Professor Wells, author of the book Accents of English, said: "You now get these features not just in the South-east but in other parts of the country. One exception is Liverpool, which has such a strong accent of its own."
Nationally there are more than 80 expressions for being left -handed, yet "cack-handed", a term borrowed from the South-east, is now the most commonly used in much of northern England.
In order that words are not lost forever, the University of Sheffield is about to undertake the first national survey of regional English for 40 years which will take a decade to complete.
The survey is being run by Dr Clive Upton and Professor John Widdowson, of the university's Centre for English Cultural Tradition and Language, who said many words were being lost.
Prof Widdowson said: "What we are seeing is a younger generation's version of standard English, which is much more of a halfway house."
As a pilot for the national survey, researchers are to compile a glossary of Yorkshire dialect, which will mark the 100th anniversary this year of the Yorkshire Dialect Society.
Readers will learn that to be "blethered after addling your brass" means that you are exhausted after working hard for your money.
"Callifudging" is an old Yorkshire expression for messing about and "manishment" has nothing to do with machismo but is a North Riding term for fertiliser.
A taste of regional vocabulary
Marrer (workmate) North East
Tab (ear) South Yorkshire
Sprack (active child) Severn estuary
Frit (afraid) East Midlands
Spelk (splinter) North East
Ochin (hedgehog) West Midlands
Backend (autumn) Northern England
Dap (bounce) South Wales
Lake (to play) Northern England
Whin (Gorse) Lake DistrictReuse content