Slough is to move to tier two Covid restrictions from Saturday, the government has announced.
The change is a response to a rise in the number of cases of the virus in the Berkshire town where the infection rate is at 153 cases per 100,000.
It means there will be new restrictions on households mixing in homes and hospitality venues.
Health secretary Matt Hancock said there was a "concerning rise" in coronavirus cases among the over 60s.
Figures published on Wednesday show a total of 1,522 people have tested positive for coronavirus in Slough, an increase of 53 on the previous day.
'Alarming rapid rise'
The change to "high risk" status will mean additional measures preventing households from mixing with one another indoors, including in pubs and cafes.
However there are exemptions for circumstances such as childcare and for support bubbles.
Multiple households can also gather outdoors and in private gardens up to a maximum of six people.
Slough MP Tan Dhesi announced the change following a meeting with health minister Nadine Dorries, saying there had been an "alarming rapid rise" in local coronavirus cases.
"I appreciate these measures will be difficult for many within the community, but please follow government guidance, so that we can protect our NHS, and the lives and livelihoods of our loved ones," he said.
Speaking in the House of Commons, health secretary Matt Hancock said Slough would be moved to tier two along with Stoke-on-Trent and Coventry.
"In all of these areas there is over 100 positive cases per 100,000 people, cases are doubling around every fortnight, and we're seeing a concerning rise in cases among the over 60s.
"I can assure the people of Stoke-on-Trent, Coventry and Slough that we'll support you all the way through."
James Swindlehurst, leader of Slough Borough council, said the town had not had a "major outbreak around a particular venue or shop like other areas", but added infection was spreading due to "community transmission".
Elsewhere in Berkshire, the Royal Borough of Windsor & Maidenhead has received approval from the government to remain in tier one for the time being.
Andrew Johnson, leader of the council, said: "Last week given our borderline status and likely projected increase in cases I asked government to consider whether it was appropriate or not for us to move into high-risk tier two.
"Since then the rise in our number of cases has slightly abated, but the potential for underlying infection remains extremely high.
"Our numbers are such that we remain on the cusp of tier two and all the additional restrictions on our lives this would bring.
"We must not be complacent. We must continue to follow the guidance. We must stop the spread. Doing this may help us avoid tier two."