The proportion of people in England receiving an in-person Covid-19 test result within the Government's 24-hour target period has hit its lowest point since the middle of June, new data shows.
Official NHS Test and Trace figures also showed that the weekly number of positive tests in England has risen to its highest level since the system was launched at the end of May.
Some 33.3% of people who were tested for coronavirus in England in the week ending September 9, at a regional site, local site or mobile testing unit – a so-called "in-person" test – received their result within 24 hours.
This is the lowest proportion since the week to June 17, when the figure stood at 31.3%.
The 33.3% figure is also down from 66.5% in the previous week, according to statistics released by the Department of Health and Social Care (DHSC) on Thursday.
Prime Minister Boris Johnson had previously pledged that, by the end of June, the results of all in-person tests would be back within 24 hours.
Meanwhile, a total of 18,371 new people tested positive for Covid-19 in England in the week to September 9.
This is an increase of 75% in positive cases on the previous week, and is the highest weekly number since Test and Trace was launched at the end of May.
The figures come amid a spike in infection rates in some parts of the country, with the North East set to become the latest area in England to come under local restrictions.
NHS Test and Trace statistics [since launch]
➡️ 5.9 million individuals tested for the first time
➡️ 417,296 people reached by NHS Test and Trace
➡️ 87% of identified close contacts who provided contact details reached
Read the full report 👇https://t.co/8WIuu9sjxa
— Department of Health and Social Care (@DHSCgovuk) September 17, 2020
Mr Johnson admitted to MPs on Wednesday that there is not enough capacity in the testing system, after demand "massively accelerated" in recent weeks.
The latest data also shows that just 1.9% of people in England who used a home test kit for Covid-19 received their result within 24 hours in the week to September 9, the lowest percentage since Test and Trace's launch at the end of May.
Some 9.3% of people received the result of a home test within 48 hours, the lowest percentage since the week to June 10, when the figure stood at 9.1%.
DHSC statistics also show that some 73.9% of close contacts of people who tested positive for Covid-19 in England were reached through the Test and Trace system in the week ending September 9.
This figure is up from 69.5% on the previous week, but below the 77.2% reached in the week to August 19.
Local health protection teams fared better in their efforts to reach contacts, with cases handled by them reaching 98.9% of contacts and asking them to self-isolate in the week to September 9.
By contrast, for cases handled either online or by call centres, 63.7% of close contacts were reached and asked to self-isolate.
Since the launch of Test and Trace, 339,438 close contacts of people who have tested positive for Covid-19 have now been reached through the tracing system and asked to self-isolate.
Matt Hancock's statement to the House announces new restrictions in the North East and various investments in a&e departments and care homes but says virtually nothing about the testing chaos engulfing the country!!
— Justin Madders MP (@justinmadders) September 17, 2020
This is 78.1% out of a total of 434,612 people identified as close contacts.
The remaining 95,174 people (21.9%) were identified as close contacts, but were not reached.
On Thursday, the Government announced that it was launching two new "Lighthouse" testing labs in Newcastle and Bracknell.
Accompanying new sites in Newport and Charnwood, the four labs will help increase capacity to deliver 500,000 tests per day by the end of October, DHSC said.
NHS Providers, which represents NHS trust leaders, argued that the country was "a long way off where we need to be with testing".
Deputy chief executive Saffron Cordery said trust leaders were "increasingly concerned" that testing shortages could put pressure on NHS services and winter preparations due to growing staff absences.
"Trust leaders are concerned that they do not have the detail on why there are shortages, how widespread they are or how long they will last," she added.
Reacting to the latest test and trace figures, Justin Madders, Labour's shadow health minister, said it was a "huge concern" that the test and trace system performance "continues to go backwards" and appeared "on the verge of collapse".
He added: "Perhaps the biggest problem is that people cannot get tested, which means thousands of people are not going into the system in the first place. Ministers must get a grip and fix testing now."
In Parliament on Thursday, shadow commons leader Valerie Vaz questioned why the Government's head of the coronavirus Test and Trace programme, Baroness Dido Harding, has not spoken in public since August.Fcase
Baroness Harding, who is interim executive chairwoman of the National Institute for Health Protection, is due to give evidence to the Commons Science and Technology Committee on Thursday.