Surge testing has been introduced in a new part of the country as the Indian covid variant continues to spike infections.
Anyone over the age of 12 living in certain areas of Calderdale, West Yorkshire, will be offered tests whether they have symptoms or not.
The Department of Health said additional testing and genomic sequencing will take place in the Todmorden, Park and Warley wards as a result of cases of the Delta variant being identified there.
Enhanced contact tracing is also being implemented while those identified as having the variant have been told to self-isolate and their contacts have been notified.
Surge testing is an approach the government has been adopting since February and which sees increased testing being carried out in a specific area where a rise in cases has been recorded.
It was last rolled out in specific postcode areas of Reading and Wokingham, Berkshire after cases of the Delta variant, which was first identified in India, were detected.
Before that it was launched in Bradford,West Yorkshire, and Canterbury and Maidstone in Kent after cases of the variant were identified there too.
It comes during a "critical" time for the government as they have a week left to make up their mind as to whether they will go ahead with the further lifting of lockdown on June 21.
Concerns have been raised over the safety of going through with the government's fourth and last step to exiting lockdown amid a recent spike in Covid cases.
According to the former chief scientific adviser to the UK government, there is evidence of a third wave starting just as people in England enjoy more freedom to go out and socialise.
Sir David King told Sky News on Monday: "[There are] 5,300 new cases of the disease per day in the United Kingdom and we're up about 2,000 on last week.
"Now we've been discussing whether or not we're going into a serious third wave and I don't think we can possibly wait any longer. This is the evidence of another wave appearing."
Ministers, experts and advisers will this week begin examining crucial data which will decide whether step four of the unlocking “roadmap” can be triggered on June 21, removing all remaining legal restrictions.
Boris Johnson is due to make an announcement next Monday.
Health Secretary Matt Hancock on Sunday warned the government was prepared to delay the June 21 unlocking if necessary.
Advice on face masks, social distancing and working from home could remain after June 21 even if other easings go ahead, it is reported today.
On Sunday 6 June, there were 5,341 new cases and four deaths within 28 days of a positive test.
Across the UK more than 40m people have now had at least one dose of a Covid vaccine while more than 27m have received their second one too.
