The prime minister will make a televised address on Monday night outlining the steps necessary to tackle the rise in coronavirus cases.
A No 10 spokesman said: "The spread of the new variant of Covid-19 has led to rapidly escalating case numbers across the country.
"The prime minister is clear that further steps must now be taken to arrest this rise and to protect the NHS and save lives.
"He will set those out this evening."
It is expected to take place at 8pm. Parliament is then set to be recalled on Wednesday, Downing Street has said.
On Monday morning, Mr Johnson said there was "no question" about the need for tougher measures which would be announced "in due course". Health secretary Matt Hancock also, speaking to the BBC, said the government would not rule out a national lockdown.
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