Long queues have been formed after extra coronavirus testing facilities were set up in two south London boroughs as dozens of new cases of the South African variant were detected.
Some 44 confirmed cases of the variant have been found predominantly in Lambeth and neighbouring Wandsworth, with a further 30 probable cases identified, the Department of Health and Social Care (DHSC) said.
People aged 11 and over who live, work or travel through those areas are being urged to take a Covid-19 polymerase chain reaction (PCR) test, on top of using twice-weekly rapid testing.
Lambeth Council said eight additional testing sites have opened across the borough from Monday and facilities are also available in Wandsworth.
Ministers are under pressure to tighten quarantine laws after the cluster of cases emerged.
Downing Street insisted the outbreak was being taken “very seriously” and “strong measures” had been put in place to prevent the spread of the variant.
But Labour said the development was “deeply concerning” because of concerns that vaccines could be less effective against variants.
Shadow home secretary Nick Thomas-Symonds has written to Priti Patel to call for a “comprehensive” hotel quarantine system.
The BBC reported that the outbreak appears to have been triggered by an individual who travelled from Africa in February.
According to documents seen by the broadcaster, the country involved was not on the red list for mandatory hotel quarantine at that time, but is now.
In his letter to the home secretary, Mr Thomas-Symonds said: “Labour has consistently called for a comprehensive hotel quarantine system, to do everything possible to stop variants reaching the UK.
“However, the UK government has refused to act on these warnings and the prospects of further outbreaks remain incredibly concerning.
“Sadly the outbreak in south London is an example of what can occur when action is not taken.”
The prime minister’s official spokesman told reporters: “I think this is something that we are taking very seriously and the effective surge testing processes that we have in place have been working well here.
“We know that variants do pose a risk, it’s one of our four tests for the progression of the road map. But… we have strong measures in place to find and isolate any new cases.”
