Health Secretary Matt Hancock faced questions in the House of Commons over coronavirus testing failures in Bolton and Bury.
Mr Hancock was grilled following reports over the weekend that one testing site failed to turn up in Bolton, leaving a car park 'filled with sick people', and that hundreds of people in Bury queued for hours for a test.
Shadow Health Secretary Jonathan Ashworth said: "Over the weekend in Bolton, where infections are highest in the country, a mobile testing centre failed to turn up. Meanwhile in Bury, hundreds queued for five hours for a test."
The concerns about Bolton and Bury came alongside criticism that the testing systems continues to be overwhelmed at a 'perilous moment' when cases continue to increase across the UK.
"Increasing numbers of teachers and pupils are not in school," added the shadow secretary.
"In hospitals operations are cancelled while NHS staff are stuck in limbo waiting for tests, and the health secretary blames increased demand.
"But when tracing consistently fails to reach 80 per cent of contacts, when less than 20 per cent of those with symptoms self-isolate properly, and there is a lack of financial security - infections rise.
"When schools reopen and people return to workplaces and social distancing becomes harder - infections rise.
"Extra demand on the system was inevitable. So why didn't he use the summer to significantly expand NHS lab capacity and fix contact tracing?
"And just as demand is increasing, the ability to process tests is diminishing. Post grad students working in the Lighthouse Labs are returning to university. So why did he not plan for these inevitable staff shortages in the Lighthouse Labs?"
Mr Ashworth also said there was a backlog of hundreds of thousands of tests being processed, delaying results from being handed out in 24 hours, a promise made by the Prime Minister.
But the Health Secretary did not directly address the concerns raised about Bolton and Bury.
Instead, he said: “The good news is that capacity for testing is at a record high."
Mr Hancock then gave figures for the amount of tests being carried out in the 10 local authorities with the highest number of coronavirus cases at swab centres, saying: "We processed yesterday 9,278 tests at Pillar 2 sites, those outside of the NHS testing capacity in those top 10 local authority areas.
"Record numbers of people are able to get tests.
“I don’t deny that it’s a enormous challenge, and when you have a free service it’s inevitable that demand rises. The challenge is to make sure we prioritise the tests we have as a nation for those who most need it."
The backlog is 'falling' at less than one day of processing capacity, added the MP, saying: "We will deliver on the challenges of today, I don't deny those challenges, but what I do is face the facts to deliver on those challenges rather than simply complaining."
