The UK is at a “critical point” in the coronavirus pandemic and “heading in the wrong direction”, the government’s chief medical adviser will warn.
Prof Chris Whitty believes the country is facing a “very challenging winter period” and is hold a televised briefing at 11:00 BST.
It comes after the prime minister spent the weekend considering whether to introduce further measures in England.
On Sunday, a further 3,899 daily cases and 18 deaths were reported in the UK.
The prime minister is understood to be considering a two-week mini lockdown in England – being referred to as a “circuit breaker” – in an effort to stem widespread growth of the virus.
He held a meeting at Downing Street on Sunday, along with Prof Whitty, Chancellor Rishi Sunak and Health Secretary Matt Hancock, to discuss possible measures.
BBC political editor Laura Kuenssberg said the view from No 10 was that while doing nothing “was not an option”, neither was a full national lockdown, and that whatever measures are imposed could be turned “off and on” throughout the winter.