Volunteers have begun delivering throusands of coronavirus testing kits as part of a push to identify cases of the South African variant of COVID.
Several more cases of the strain, which experts are worried may be more resistant to the vaccines, were identified in parts of the country over the weekend.
Health secretary Matt Hancock said at Monday’s Downing Street press conference that the government would be ramping up testing in the postcodes where cases were found.
And on Tuesday, volunteers began door-to-door delivery of home testing kits as the government is aiming to swab 80,000 people.
More than 100 volunteers are due to help deliver tests within the GU21 postcode area of Woking in Surrey, one of eight postcode areas being targeted across the country.
A first briefing was held on Monday morning outside the town's fire station, with local officials hoping the operation will take four or five days.
Plans involve delivering PCR tests, which are not compulsory, for around 9,500 residents living in an area within the GU21 postcode.
Two cases of the South African variant of coronavirus have been identified in Woking but local residents should not be concerned, the leader of Surrey County Council said.
Tim Oliver said: "There have been two cases identified in the postcode GU21 here in Woking of people that have the South African variant.
"What we're doing today is starting a mass testing programme of between 9,000 and 10,000 residents living in that geographical area, really with the view to discovering how far and wide that variant has spread, or maybe it hasn't."
Watch: Testing ramped up in west London amid South Africa strain spread
Oliver added: "We want as many people as possible to take the test but it's not compulsory at all, it's voluntary.
"There's no need for people to worry or panic about this. It's just an exercise to identify where this variant is sitting in the community."
He said: "They shouldn't be concerned; it's a bit more virulent, as we know, than some of the other variants, but the symptoms are the same."
Volunteers will drop off testing kits and return later in the day to collect them before the tests are sent off to a lab to be examined for the South African strain.
They will revisit homes on another occasion if people are not in.
A spokeswoman for Surrey County Council said the tests are to be completed by members of households over the age of 18.
Mobile testing units and home testing kits will also be deployed to the following areas: Hanwell, west London; Tottenham, north London; Mitcham, south London; Walsall in the West Midlands; Broxbourne, Hertfordshire; Maidstone, Kent; and Southport, Merseyside.
However, one Woking resident said he believed the tests are "a bit of a waste of time" if people are going to work.
Stewart Dawkins, 58, a key worker for a supermarket, said: "I think it's a bit of a waste of time to be honest.
"They've asked you to do this (complete a test) but I'm OK to go to work yesterday.
"What about all the people I've gone and potentially passed it on to last night at work?"
Another Woking resident said said it was "concerning" that the South African variant had been detected locally.
Robyn Brunskill, 22, who works for a marketing agency, said: "It is quite concerning, especially if they are saying people who have it haven't had any direct association with South Africa.
"That makes you worry about where it's coming from and you're more vulnerable than you think you are."