Birmingham, Sefton and Central Bedfordshire are "most likely" to be next in line for tough Covid guidance as cases continue to surge, an expert has said.
Professor David Livermore, an epidemiologist at the University of East Anglia, said the dominance of the strain in such places means surge testing and tougher travel guidance are imminent.
The Indian variant - now known as Delta - makes up more than 85 per cent of all new infections in Birmingham, putting it fifth in the country for cases of the strain.
And it is also dominant in neighbouring areas like Walsall, Sandwell, Dudley and Wolverhampton which have each identified at least 30 cases, figures show.
It comes after Greater Manchester and Lancashire were yesterday added to a list of eight other parts of the country where surge testing and stricter travel advice has been imposed as the mutation surges.
Have you been hospitalised with the Indian/Delta variant? Let us know at webnews@mirror.co.uk
A total of 28 councils across England are now subject to the guidelines, with the Army having been dispatched to boost testing and vaccination efforts, with residents warned not to leave their immediate areas.
Official data shows just six of the 10 places to have confirmed at least 150 cases or more of the Delta strain have been made subject to the new advice.
Birmingham has 223, Sefton, in Merseyside, has 193, (60 percent of overall cases), Nottingham 192 (79.3 percent) and Central Bedfordshire 183 (89.7 percent) but have all not yet been added to the list.
While 148 Delta cases or 76.4 percent have been found in Hillingdon, 137 or 94.4 per cent in Croydon, and 119 in Luton (119), among the highest risers also not included yet.
Professor Livermore told the Daily Mail : "I’m loth to best guess what the Government will do but they are most likely to pursue such approaches in places where the Indian variant is most prevalent and where its incidence in the population is also high."
He said such an approach may not be enough to cut down on case numbers despite hospitals unlikely to be overrun at any rate with the vaccination programme moving so quickly.
Some SAGE advisers fear a huge uptick of the mutation - believed to be 40 percent more transmissible than the formerly dominant Kent, or Alpha - is possible.
Some modelling suggests hospitalisations could hit the horrific levels seen at the height of the last wave, despite over 80 percent of Brits having had at least one jab.
Professor Livermore said while Delta appears more than capable of becoming nationally predominant as Alpha was in November, particularly under "laxer conditions of 'guidance'" - he said there is hope.
"This will be slowed by growing herd immunity and the coming of summer," he said, adding: "Despite this inevitable spread, and rising case numbers, there is scant evidence of rising severe disease and none that NHS is still under severe Covid pressure."
The Government is crossing its fingers similar measures taken in Delta hotspots like Bolton - which saw the infection rate quickly dip after surge testing was introduced - will stamp out any outbreaks.
Hospital admissions have also begun to drop off in the Greater Manchester borough.
The specific areas included in the new guidance in Greater Manchester are: Manchester, Salford, Bury, Rochdale, Wigan, Oldham, Stockport, Trafford, Tameside and Bolton.
And in Lancashire: Rossendale, Hyndburn, Ribble Valley, Preston, South Ribble, Chorley, Pendle, Fylde, Lancaster, West Lancashire, Wyre, Burnley and Blackburn with Darwen.
While the 28 is rounded off with Kirklees, Hounslow, Leicester, North Tyneside and Bedford.
Comparing Department of Health infection rates on June 3 with those from a week before, show Staffordshire Moorlands, Cheltenham, Newcastle-under-Lyme, Tewkesbury, Cheshire East and Chester and Elmbridge all had rising Delta cases.
Maldon, Adur and Rochford had no cases of the variant but hadn't done much sequencing, while Eden had done none despite a surging general infection rate.
