Wandsworth council has described the testing operation as a “mammoth task” but urged all people over the age of 11 in the area to get tested even if they do not have any symptoms.
Residents in the SE16 postcode of Southwark were also today told to take a test after a case of the South African variant was found there.
Tom Billington, 30, joined the queue at Clapham Common.
He said: “It’s concerning this has come along just as we are starting to get back to normal. But as long as everyone does the right thing and gets tested I think it will be alright. I’ve had both doses of vaccine so I’m feeling confident but we’ve all got to be responsible and do our bit.
“But it isn’t going to make me change any plans unless my test is positive.”
Thousands of people joined lines at pop-up centres on Clapham Common and in Brockwell Park this morning.
To bring down waiting times centre marshals gave out home testing kits and many residents sat on the grass in groups completing the swabs themselves.
Classical singer Charlotte Brosnan, 33, said: “It’s good so many people seem to have come out for this.
“We have had a year of being locked down and being told to get tested all the time so it just feels normal.
“It’s slightly concerning that we don’t know much about this variant but it hasn’t made me think about changing any plans. It’s just another thing we’ve got to deal with.”
Daniel Fagen, 33, said: “I think it is a bit scary and I want to get out there and do my bit to make sure I’m not spreading it around. But it won’t.
Obviously I’ll wait for my test results and if I’m positive I’ll isolate but it won’t stop me going out or living life at the moment.”