Public Health England has urged people to wear masks in enclosed spaces after coronavirus restrictions are eased on July 19 amid a “rapid” rise in cases.
Health officials said people should “remain vigilant” and take steps to protect themselves.
These include wearing a mask in enclosed spaces and opening windows when meeting indoors.
As of Wednesday, there had been a further 42,302 lab-confirmed Covid-19 cases in the UK, the Government said, the highest daily reported rise since January 15.
Public Health England (PHE) said that deaths and hospital admissions had not risen as rapidly as cases thanks for the vaccination programme.
But it urged people to take steps to protect themselves as England prepares to lift Covid restrictions on July 19.
The Government reported that a further 49 people had died within 28 days of testing positive for Covid-19 as of Wednesday.
It brings the UK total to 128,530.
Separate figures published by the Office for National Statistics show there have now been 154,000 deaths registered in the UK where Covid-19 was mentioned on the death certificate.
PHE warned that “the pandemic is not over”.
Dr Yvonne Doyle, medical director at PHE, said: “Cases are rising rapidly.
“We knew that as we opened up cases would increase, but thankfully due to the vaccine, deaths and hospital admissions are not rising as fast as cases.
“If you have not had the vaccine, book your first and second dose as soon as you can.
“Restrictions are currently still in place, it is important to follow them, and when they lift on Monday there are still steps we can all take to protect ourselves and loved ones such as wearing a mask in enclosed spaces, opening a window if you’re meeting in close contact indoors, and getting tested and staying at home if you have symptoms.
“The pandemic is not over, and we must all remain vigilant.”