The number of such positive test jumped on Sunday to 2,249, from 721 on Saturday and 943 the previous day.
On Monday, the figure was 1,478 and the numbers for the most recent days could rise further.
It may be picking up more cases among family members who are also being offered use of the rapid flow devices to check whether they have the virus.
More than 9,000 firms have also signed up to offer the lateral flow tests to their employees to identify cases in factories, offices and other work venues, with at least a further 39,000 businesses having expressed an interest in using the quick result devices.
For secondary school pupils, the first three tests for the return to class on March 8 were supposed to have been done on site at schools and colleges under supervision, giving results from the lateral flow tests in around 30 minutes.
After that, pupils should have been given lateral flow device testing kits by their school or college to take home.
All secondary school pupils and college students, as well as staff, should be doing two tests a week as part of the huge programme to pick up asymptomatic cases of the virus.
Members of a household, childcare or support bubble of a pupil, student or staff of a school or college can also get a twice-weekly test.
This can be done through the individual’s employer in some cases, at a local asymptomatic test site, by collecting a home test kit from a test site, or by ordering a home test kit online.
Staff at private, voluntary and independent nurseries should also have access to rapid testing through their workplace.
The daily number of positive lateral flow tests has not been above 2,000 since mid-January when disease levels were far higher.
So the huge surge in testing means the daily confirmed cases figures need to be treated with caution, as they are being pushed up by the extra testing rather than necessarily because the disease is spreading.
Public health chiefs in London believe the virus is still on the retreat though they expect it to take longer to tail off than after the first wave.
Official figures show that:
- The seven-day rate in London was 36.5 confirmed new infections per 100,000 in the week to March 18, down 7.4 per cent on the previous week.
- The lowest rate in the capital was Hackney and the City of London on 15.8, with the highest Hillingdon on 72.3.
- Twenty-one boroughs saw cases fall in the week to March 18, with 11 having rises.
- The biggest increase was in Islington, of 71.9 per cent, though from a low base to a rate of 40.4.
- The biggest fall was Waltham Forest, down 37.5 per cent.
A further 35,416 first dose jabs were announced yesterday to have been administered in London, taking the total so far to 2,900,430.
An additional 7,444 second dose inoculations were announced yesterday to have been administered in the capital, taking the total so far to 219,377.
The detailed figures for London show:
- Waltham Forest saw 80 cases in the week to March 18, down 48 (37.5%) with a seven-day rate of 28.9
- Barnet 95 cases, down 44 (31.7%) rate 24
- Camden 58 cases, down 23 (28.4%) rate 21.5
- Hackney and City of London 46 cases, down 18 (28.1%) rate 15.8
- Croydon 104 cases, down 33 (24.1%) rate 26.9
- Kingston 85 cases, down 24 (22%) rate 47.9
- Barking and Dagenham 78 cases, down 19 (19.6%) rate 36.6
- Bexley 62 cases, down 15 (19.5%) rate 25
- Havering 89 cases, down 20 (18.3%) rate 34.3
- Harrow 132 cases, down 27 (17%) rate 52.6
- Hammersmith and Fulham 58 cases, down 10 (14.7%) rate 31.3
- Ealing 211 cases, down 36 (14.6%) rate 61.7
- Kensington and Chelsea 37 cases, down 6 (14%) rate 23.7
- Sutton 79 cases, down 10 (11.2%) rate 38.3
- Bromley 90 cases, down 10 (10%) rate 27.1
- Redbridge 136 cases, down 15 (9.9%) rate 44.6
- Lambeth 97 cases, down 10 (9.3%) rate 29.8
- Newham 151 cases, down 8 (5%) rate 42.8
- Hillingdon 222 cases, down 10 (4.3%) rate 72.3
- Haringey 72 cases, down 3 (4%) rate 26.8
- Tower Hamlets 115 cases, down 3 (2.5%) rate 35.4
- Lewisham 84 cases, up 1 (1.2%) rate 27.5
- Brent 160 cases, up 3 (1.9%) rate 48.5
- Richmond 70 cases, up 4 (6.1%) rate 35.4
- Hounslow 169 cases, up 10 (6.3%) rate 62.2
- Enfield 100 cases, up 7 (7.5%) rate 30
- Wandsworth 120 cases, up 9 (8.1%) rate 36.4
- Southwark 79 cases, up 10 (14.5%) rate 24.8
- Greenwich 114 cases, up 15 (15.2%) rate 39.6
- Westminster 87 cases, up 12 (16%) rate 33.3
- Merton 97 cases, up 19 (24.4%) rate 47
- Islington 98 cases, up 41 (71.9%) rate 40.4