Cockney speakers are now more likely to live in Essex than in the traditional heartlands of inner London's East End, according to research.
Historically the dialect was used by people from the central-eastern boroughs of the capital, but a new multicultural way of speaking has emerged there in recent years.
Dr Sue Fox, a socio-linguistic expert from Queen Mary, University of London found features of the traditional Cockney dialect are now more likely to be heard in Basildon or Barking than within the sound of Bow Bells or modern-day Tower Hamlets - where it originated.
She said: "In the last five decades Cockney has probably undergone more rapid change than at any time in its long history.
"Without doubt the speech forms associated with Cockney can still be heard but ,with the multicultural diversity we now see in the East End, the Cockney label would seem to be becoming less and less relevant to the people living there."
According to Dr Fox's research, since the 1950s a vast number of the white working class-families which predominated in the East End in the early part of the 20th century have moved to other parts of the country such as Essex.
The once rural areas have now been urbanised and are now filled with Eastenders and their descendants.
She added: "The sheer number of people who have moved from the traditional East End into the surrounding areas of London, and in particular Essex, have ensured that the influence of Cockney is still exerted in these areas and it is there that many features of the dialect can still be heard."