Carlisle is heading into Tier 2 lockdown measures, with restrictions coming into force in just a few hours at midnight tonight.
Residents of Carlisle and its surrounding areas will no longer be allowed to meet people from another household indoors or gather in a group of more than six outside.
It comes after the city's coronavirus infection rate shot up from 176 cases per 100,000 people to 231 in a week, Cumbria County Council said.
The council tweeted: "COVID-19 ALERT: Following a decision by Government, Carlisle and all its surrounding areas including communities such as Longtown and Brampton will be moved from medium to high risk on the local COVID-19 alert levels at midnight tonight."
A Cumbria County Council spokesman said: "The change means that from midnight it will be illegal to meet indoors with people outside of your own household or bubble. Outdoors the ‘rule of six’ remains unchanged."
"The announcement follows rising cases in Carlisle and this week’s Public Health update which showed Carlisle overtaking Barrow borough in having the greatest number of new cases in the county.
"Barrow and Carlisle’s rates are currently higher than the national average."
The Department of Health and Social Care said the decision on Carlisle moving to Tier 2 of coronavirus restrictions from Saturday came after discussions with local leaders.
"The rate of Covid-19 infections is rising rapidly across the UK," it said.
"The weekly case rate in England stood at 226 people per 100,000 from October 18 to October 24, up from 100 people per 100,000 for the week September 25 to October 1. Cases are not evenly spread, with infection rates rising more rapidly in some areas than others.
"In Carlisle, weekly case rates stand at 233 people per 100,000. This increases to 244 per 100,000 in those aged 17-21 and is 206 per 100,000 in the over 60s."
It comes after the UK's coronavirus death toll shot up by 274 today, while infections increased by more than 24,000.
This is the biggest Friday jump in deaths since May 29, when 274 fatalities were also recorded.
A further 24,405 positive cases were logged over the past 24 hours.
Infections are soaring across the country and some hospitals are now treating more Covid-19 patients than during the peak of the pandemic in April.