A coronavirus testing blitz will be carried out in Surrey, Southampton and Norfolk following confirmed cases of the South Africa Covid variant in the commuter regions.

Surge testing and genomic sequencing will be carried out in the GU22 postcode in Woking, SO15 in central Southampton and IP22 in Diss to tackle the “variant of concern”.

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People living in the targeted areas are strongly encouraged to take a Covid-19 test this week whether they are showing symptoms or not, the Department of Health and Social Care (DHSC) said in a statement.

The affected postcodes will receive knocks on the door asking them to take coronavirus tests over the coming days.

DHSC added that surge testing in the London borough of Haringey which began last week is now complete and further data on surge testing will be provided in due course.

Other London areas including Lambeth, Ealing and Croydon are still undergoing surge testing as the capital scrambles to fend off cases of “variants of concern”.

It comes after the government’s virus threats advisory group announced today that a new Covid variant has been identified in “geographically dispersed” regions across England.

Public Health England (PHE) said it has identified 38 cases of the new strain, which genomic sequencing has shown to feature a specific set of mutations currently referred to as B1525.

The set of mutations includes the E484K spike protein mutation, which is thought to be partially resistant to available vaccines. The E484K mutation is present in the South Africa, Brazil and Bristol strains of coronavirus.

Speaking in the Commons earlier this month, health secretary Matt Hancock said 11 cases of mutant strains were identified in Bristol and 32 in Liverpool.

He promised to “come down hard” on cases of the new variant, urging people in affected areas not to leave their houses unless absolutely necessary.

“It is imperative that people must stay at home and only leave home where it is absolutely essential. When your local authority offers you a test, you should take up the offer, because we know that around one in three people with coronavirus have no symptoms but can still pass it on,” Hancock told MPs.

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Jonathan Van-Tam, England’s deputy chief medical officer, has insisted that it is unlikely any of the “variants of concern” will become dominant in the UK.

Van-Tam told a Downing Street press conference last week that the UK’s only “immediate threat” remains a new Covid strain first identified in Kent, which is thought to be receptive to available vaccines.