The UK set another daily record of nearly 23,000 new coronavirus cases on Sunday night – as the government claimed the figure was "artificially high" because of a computer glitch.
Public Health England revealed that the official Covid dashboard had failed to count more than 15,000 positive results reported between 25 September and 2 October. They have instead been added to the figures for the weekend, resulting in record rises of 12,872 on Saturday and 22,961 on Sunday.
Officials admitted that the backlog meant contact tracing for those cases had been potentially delayed for more than a week, but insisted that it had not affected “decision-making in local areas”.
Labour's shadow health secretary Jonathan Ashworth and shadow justice minister David Lammy both described the situation as "shambolic".
“People across the country will be understandably alarmed,” said Mr Ashworth."Matt Hancock should come to the House of Commons on Monday to explain what on earth has happened, what impact it has had on our ability to contain this virus and what he plans to do to fix test and trace."
It came as a leaked document – which has been seen by The Guardian and appears similar to one published online by the BBC – revealed more detail about the government's plans for a 'three-tier' lockdown.
The most severe measures envisaged by the traffic light-style scheme for England involve the closure of all hospitality businesses and the banning of all social contact between households.
They would be triggered nationwide when lower level restrictions had failed to contain the spread of Covid-19 but could also be imposed on regions with "a significant rise in transmission" of the virus, the documents say.
The Department of Health refused to comment on the leaks but has previously indicated that it is considering a standardised system to replace the patchwork process of local restrictions which has been built up over the last three months.
A spokesperson said: “We are seeing coronavirus cases rise at a rapid rate across the country and, given how serious this virus is, it is vital everyone plays their part by following the rule of six, washing their hands, practising social distancing and wearing a mask in enclosed spaces.
“As we have shown, we are prepared to take action decisively when it is necessary, and it is of course right to look how we make sure everyone understands and complies with the restrictions that will keep us all safe.”
The recent surge of confirmed cases takes the UK's total for the pandemic to over 500,000.
Official figures for the number of patients in hospital have also started to increase, with 422 admitted on 29 September. The total as of 1 October stands at 2,428, which is still well below the peak of about 20,000 in April.
A further 33 deaths were reported on Sunday, bringing the total number of deaths within 28 days of a positive Covid test to 42,350. However, other official statistics show that there have now been nearly 57,900 deaths registered in the UK where Covid-19 was mentioned on the death certificate.
According to a note added to the government’s official Covid dashboard, which provides daily data on cases, deaths and hospitalisations for the UK, the daily figures for Saturday and Sunday are "artificially high for England and the UK".
Michael Brodie, the interim chief executive at PHE, said the "technical issue" was identified overnight on Friday 2 October in the data load process that transfers Covid-19 positive lab results into reporting dashboards.
“After rapid investigation, we have identified that 15,841 cases between 25 September and 2 October were not included in the reported daily Covid-19 cases. The majority of these cases occurred in most recent days,” he said. "Every one of these cases received their Covid-19 test result as normal and all those who tested positive were advised to self-isolate.
"NHS Test and Trace and PHE have worked to quickly resolve the issue and transferred all outstanding cases immediately into the NHS Test and Trace contact tracing system and I would like to thank contact tracing and health protection colleagues for their additional efforts over the weekend.
“We fully understand the concern this may cause and further robust measures have been put in place as a result.”