UK reports 6,000 new coronavirus cases
It follows a rise of 4,926 the day before, and brings the total confirmed cases in Britain since the pandemic hit to 409,729.
With a further 37 deaths reported in the past 24 hours, 41,862 people in Britain who tested positive for the virus have now died -- the highest toll in Europe.
The director of the Rosalind Franklin Institute and professor of structural biology at the University of Oxford, James Naismith, called the spike in cases "unwelcome news".
"It is part of a trend and there is no doubt the virus is taking off again," he added, attributing the rise to an expanded testing regime.
But he warned that the increase in cases will eventually lead to serious illness and death.
"Medical and scientific advances will significantly reduce this toll compared to the height of the pandemic, provided that hospitals are not overwhelmed by excessive numbers of cases," he added.
On Tuesday, Johnson set out plans to close pubs early and reverse previous guidance that people should go back to the office, warning the country was at "a perilous turning point".
Taking questions in parliament on Wednesday, he added: "Everybody should look at what has already happened in the first phases of this pandemic and be in no doubt that it is possible that such a thing could happen again."
Britain imposed a nationwide stay-at-home order in March to stem the spread of coronavirus, and after infection rates fell, the restrictions were eased from June.
The hospitality industry has reacted with anger to the new restrictions, which will see pubs and restaurants required to close at 10:00 pm (2100 GMT), saying they could destroy some businesses only just now getting back on their feet.
Many MPs are pushing the government to extend its furlough scheme that at its peak in May covered the wages of 8.9 million workers who might otherwise have lost their jobs.
The scheme is due to end in October, and Johnson insisted on Tuesday it could not go on indefinitely.
However, there is speculation of new economic support to come, after the prime minister said his government would deliver "further creative and imaginative schemes to keep our economy moving".
Finance minister Rishi Sunak is due to address MPs in the House of Commons on Thursday.