Crucially, experts said, the government also failed to prepare the country's labs for an inevitable spike in demand for tests as schools reopened in September and cases of everyday coughs and colds surged along with the coronavirus. Confirmed new cases in Britain, which had fallen below 600 a day in early July, have reached about 3000 a day.

The testing program is now so saturated that it has started sending overflow samples to labs in Italy and Germany. At one point on Monday (UK time), people in England's 10 riskiest coronavirus hot spots — including areas of Manchester, the second largest city — were unable to book tests. Some people were told they would have to travel 320km to get tested.

The Labour Party seized on the difficulties, barraging Matt Hancock, the Secretary of State for Health, at an appearance in the House of Commons on Tuesday (UK time).

"The Secretary of State is losing control of this virus," Jonathan Ashworth, Labour's lead lawmaker on health issues, said of Hancock. "He needs to fix testing now."

Hancock acknowledged "operational challenges" in the testing system that he said could take weeks to resolve, even as he pinned most of the blame on people seeking tests who did not have symptoms of the coronavirus.

Johnson has walked away time and again during his political career from the smouldering ruins of failed moonshots. His rosy attitude did not fade when the coronavirus landed in Britain this year, despite the pandemic's continually proving him wrong.

In mid-March, he promised to "turn the tide" on the virus within 12 weeks. His government at first downplayed the need for virus testing on a massive scale, defying the experts, and instead invested in untried antibody tests — which, as it turned out, failed to work.

After Johnson's government reversed course on viral testing and pledged to test 100,000 people a day by May 1, that goal placed such a strain on public laboratories that they were left scrambling for the supplies to meet the demand. It took until late August to push the figure above 200,000 tests in a day.

In July, he floated a "more significant return to normality" by Christmas. His pledge to build a "world-beating" contact tracing program remains unfinished; many contact tracers spent the early days of their employment watching Netflix.

Still, defying the warnings of a key government adviser, Johnson set out his new target last week for a high-speed diagnostic program that by early 2021 could test 10 million Britons a day, or every person in the country once a week. Documents obtained by The BMJ, a medical journal, mentioned a price tag of $100 billion pounds ($Aus176 billion) and acknowledged that the technology to process so many tests so quickly did not exist.

The government adviser who warned against the plan, John Bell, a professor at the University of Oxford, said in a radio interview that the problems with the government's existing testing program were a result of underestimating demand once students returned to class this month.

Beyond the uptick in demand, some officials have also suggested that shortages of staff and reagents, the chemical ingredients used in tests, also may be contributing to the crisis.

The shortages have rippled through schools, where students returned to classes at the beginning of the month, highlighting the dangers of sending children back to classrooms without a strong testing program in place.

New York Times