The length of time people with coronavirus symptoms will have to self-isolate for is expected to be increased from seven to 10 days in England.
It comes as ministers try to avoid a resurgence of the virus in the UK.
Currently, people showing the main symptoms – a new continuous cough, high temperature or loss of taste or smell – must self-isolate for at least a week.
Government officials are expected to set out details later.
The devolved nations are expected to follow the UK government’s lead. The current guidance has been adopted UK-wide.
The anticipated announcement comes after the prime minister warned of signs of a “second wave” of the pandemic in parts of Europe.
Speaking on BBC Breakfast, Health Secretary Matt Hancock did not confirm the change but said the government wanted to “take a precautionary approach” and “protect people from that wave reaching our shores”.
There have also been concerns about several local outbreaks across the UK, including in Oldham, Wrexham and Staffordshire.
Meanwhile, the government is also expected on Thursday to review the restrictions in Leicester again, a month after the city was put into extended lockdown following a spike in cases.