LONDON (Reuters) - British Prime Minister Boris Johnson announced tough new restrictions and social distancing measures for London and nearby areas on Saturday in an attempt to slow the spread of a new, highly transmissible variant of the coronavirus. - London and parts of the south east and east of England currently in the highest Tier 3 category will enter a new Tier 4 level of restrictions, roughly equivalent to England’s lockdown in November. - Residents in Tier 4 areas must stay at home, apart from limited exemptions. - Non-essential retail, indoor gyms and leisure facilities, and personal care services must close. - People must work from home if possible, but may travel to work if necessary, for example in construction and manufacturing. - People should not enter or leave Tier 4 areas and residents must not stay overnight away from home. - Individuals can only meet one person from another household in an outdoor public space. - Communal worship can continue to take place. - The measures will take effect from Sunday morning. FILE PHOTO: A woman walks past a boarded up London shop, amid the outbreak of the coronavirus disease (COVID-19), at Oxford Street, in London, Britain, October 14, 2020. REUTERS/Hannah McKay - A next formal review of the tiers system is due to take place on Dec. 30. TRAVEL - The government has asked people across the United Kingdom to stay local and consider whether they need to travel abroad. - People in Tier 4 areas will not be permitted to travel abroad apart from limited exceptions, such as for work. CHRISTMAS - People in Tier 4 areas should not mix with anyone outside their own household, but “support bubbles” will remain in place for those at particular risk of loneliness or isolation. - Across the rest of the UK, rules allowing up to three households to meet will be limited to Christmas Day only, rather than the five days previously set out. - There will be no relaxation on Dec 31, as previously announced.