The UK is to test all residents and workers in Liverpool for Covid-19.
Everyone in the city, in England's north west, will be tested from Friday -- regardless of whether they have symptoms -- the UK government said Tuesday.
"Dependent on their success in Liverpool, we will aim to distribute millions of these new rapid tests between now and Christmas and empower local communities to use them to drive down transmission in their areas," UK Prime Minister Boris Johnson said.
Liverpool mayor Joe Anderson said the mass testing effort would "help to quickly identify people who have the virus and reduce transmission substantially."
Liverpool has some of the highest infection rates in Britain. Weekly cases currently stand at 410.4 per 100,000, as of October 25, according to government data.
The region was the first to be placed in the "very high" tier of the country's Covid-19 alert system.
Missed targets, technical glitches and unreported cases have plagued the British government's attempts to build a functional Test and Trace system. The mass testing scheme is the first of its kind in the country.
Minsters previously encouraged only those with symptoms to come forward for a test, so as not to overwhelm the system.
England looks set to enter a new national lockdown on Thursday, as cases across the country surge.