Parts of Essex and Hertfordshire are also reported to be entering tier three.
Health Secretary Matt Hancock is expected to make a statement in the Commons shortly.
The tier three restrictions would see pubs and restaurants closed except for takeaway and delivery services.
MPs, reported to have been briefed on the plans by Mr Hancock, said a sharp rise in cases meant the health secretary was unable to wait until the next scheduled review of England’s three-tier system on Wednesday.
One MP said they were told that cases are doubling every seven days in the capital.
They added that the next review of the tier system would be on 23 December.
Mr Hancock is expected to use his statement to outline the financial support available to the tier three areas.
It follows warnings from London Mayor Sadiq Khan that tier three restrictions could have a “catastrophic consequence” for hospitality, culture and some retail.
What are tier three (very high) rules?
- You cannot mix indoors, in private gardens or in most outdoor venues, except with your household or bubble
- You can meet in a group of up to six in other outdoor spaces, such as parks, beaches or countryside
- Shops, gyms and personal care services (such as hairdressing) can stay open
- Bars, pubs, cafes and restaurants must stay closed, except for delivery and takeaway
- Sports fans cannot attend events in stadiums
- Indoor entertainment venues – such as bowling alleys and cinemas – must stay closed
- People are advised not to travel to and from tier three areas