Six English towns have been identified as having the highest proportion of vacant shops in Great Britain, BBC Newsnight has learned.
Dewsbury, Dudley, Hartlepool, Margate, Stockport and West Bromwich were named as the worst performers by retail analysts the Local Data Company.
The towns have vacancy rates of between a quarter and third of all stores.
In conducting its research the company visited all towns in England, Scotland and Wales between January-June 2011.
The precise ranking of the towns will be published on Thursday however, Newsnight has learned that the new data will show that the national shop vacancy rate is 14.3%.
This percentage represents a slight fall from 14.5% in December 2010.
According to the data gathered, 28,991 out of 202,158 retail units in England, Scotland and Wales were empty.
Commenting on the data, Matthew Hopkinson, business development director at The Local Data Company, said:
"At a national level we are seeing stability, but at a local town centre level we are seeing massive extremes.
"I think the reality that comes out of this is that we are seeing permanent change. The centres showing up to one in three shops vacant will never go back to what they used to be."
Retail guru Mary Portas, who is carrying out a government-backed review aimed at halting the decline of the High Street in England, told Newsnight:
"There are some towns where it is dead, the horse has bolted," she said, adding that in such towns it was time to give up on the previous model and rethink its uses.
However, she emphasised that many failing high streets remained ripe for rejuvenation given a proper assessment of what consumers wanted from them.
Watch the full report on the future of the High Street on Newsnight on Tuesday 6 September at 10.30pm on BBC Two, then afterwards on the BBC iPlayer and Newsnight website.