But what does this mean for Londoners?
Here are all the details:
Home: No mixing with other people indoors apart from your household or bubble but up to six people can meet outside in private gardens or public parks.
Hairdressers/beauty salons: Open.
Pubs and restaurants: Pubs can only open if they serve substantial meals. No household mixing indoors except for business meetings though groups of six can meet outside. Last orders at 10pm but venues open until 11pm.
Shops: All shops can open.
Theatres and cinemas: Open with distancing but the Society of London Theatre has warned capacity constraints of 50 per cent or 1,000, whichever is lower, will cause financial problems.
Work: Government advice is still to work from home if possible.
Travel: As little as possible and do not travel into Tier 3 unless really necessary.
Education: All nurseries, schools, colleges and universities open.
Overnight stays: Permitted but only within your household or support bubble.
Places of worship: Allowed but people must stick to their own household or support bubble.
Weddings and funerals: No more than 15 guests at weddings, receptions and wakes. Only 30 guests allowed at funerals.
Amateur sport and exercise: Organised adult sport can take place outdoors but not inside if it involves social mixing. All organised sport for children and elite athletes is allowed.
Professional sport: Spectator capacity is reduced to 50 per cent or 2,000 outdoors whichever is less and 1,000 indoors.
Live performances: Audiences again limited to 50 per cent capacity or 2,000 outdoors whichever is less or 1,000 indoors.
Gyms and swimming pools: Can open.