The UK recorded 52,009 new COVID-19 cases on Thursday-the first time cases have surpassed 50,000 since July 17.
This brings the total number of cases since the start of the pandemic to over 8.6 million. There were also a further 115 deaths, bringing the total to 139,146.
Earlier in the day, British Prime Minister Boris Johnson told reporters while on a trip to Northern Ireland: "We're watching the numbers very carefully every day."
"You're absolutely right the number of infections are high," he said. "But we're within the parameters of what the predictions were."
"We're sticking with our plan," he added.
Johnson said the UK was in an "incomparably better" position than last year thanks to its vaccination campaign, but warned that the country needs to "fortify ourselves further" ahead of winter.
"The numbers are high, we can see what's happening, we can see the increase, now is the time to get those booster jabs and also to vaccinate the 12 to 15-year-olds as well," he said.
As of late Wednesday, over 49.5 million Brits 12 and over have received their first doses of vaccine, or 86.2%, and over 45.4 million their second dose, or 79%.
