The controversial system is continuing to miss nearly 40% of those identified as having been near someone who tested positive in England, according to the latest statistics for October 29 to November 4.
Although there has been a slight improvement, some 60.4% of close contacts were not reached and therefore not told to self-isolate for the required 14 days.
Government advisers have consistently told the PM that an 80% contact rate is needed to make the entire service viable to break transmission of the virus and stop its spread.
The latest figure is the third worst on record, which after a new revision to the statistics is now calculated as 60.1% in the week to October 14.
The prime minister has recently admitted that the service run by Dido Harding has to get better and he had hoped to use the second nationwide lockdown to give it time to improve its performance.
But latest statistics show that the controversial £12bn system failed to reach 124,688 “close contacts” – defined as those who have spent more than 15 minutes within two metres of a positive Covid case – last week alone.
The new figure means that since the system was launched in May, a total of 723,240 people have not been reached and have been potentially spreading the virus asymptomatically.
Once again, publicly-run local tracing teams have a vastly better performance than national call centres and online tracers that are outsourced to the private sector.
For cases managed by local health protection teams, 99.1% of contacts were reached and asked to self-isolate in the week to November 4.
For cases managed either online or by call centres, 59.0% of close contacts were reached and asked to self-isolate.
There was better news on testing turnaround times, with 37.6% of people who were tested in England at a regional site, local site or mobile testing unit – a so-called “in-person” test – received their result within 24 hours.
This is up from 26.4% in the previous week, but still well short of the 100% pledge Johnson had told MPs he would hit by the end of June.
Shadow health minister Justin Madders said: “Although the recent decline in performance has at last been halted, performance of Test and Trace is still a million miles away from where it needs to be.
“Given the government has trusted local councils with the responsibility to administer the rapid tests it seems they have at last admitted they are the best people for the job and so it’s time they put Serco out of their misery.
“The time this lockdown buys us should be used by the government to get Test and Trace on track to prevent the virus spiralling out of control again. If this time isn’t used wisely, the public will not forgive ministers’ incompetence.”
One extra complication was revealed by the department of health and social care’s briefing note on the numbers, which cover the last week before the second lockdown in England began in early November.
“In the latest week, the number of contacts identified decreased by 4% compared to the previous week. This comes as a change from the sharp
upward trend seen since the end of August,” it said.
The drop in contacts identified – as opposed to reached – could point to the public reducing their social contacts in anticipation of the new lockdown, or it could suggest more problems in people refusing to give details of people close to them.
A total of 149,253 people tested positive at least once in the week to November 4.
This is the highest weekly number since Test and Trace was launched – an increase of 8% in positive cases on the previous week.
Harding this week rejected calls to stop referring to her heavily outsourced service as “NHS Test And Trace”, saying: “That is its name.”
The former boss of telecom firm TalkTalk, who was given her current role by health secretary Matt Hancock earlier this year, defended the use of the private sector.
“NHS Test and Trace is a free at the point of need service that we’ve built together, as you’ve rightly listed, with a whole group of different parts of society to deliver something at extraordinary scale,” she told MPs on the science and technology committee.
“But it absolutely meets our basic fundamental NHS values as a clinical service available to everyone when they need it.”