A food factory in Northampton where almost 300 people tested positive for coronavirus has been temporarily closed down.
A total of 287 cases were recently confirmed at the Greencore site in the town.
The factory employs more than 2,000 people and makes sandwiches for M&S.
The factory conducted its own testing programme after 79 workers tested positive for Covid-19 through the national NHS tests.
That testing programme went on to identify more than 200 additional confirmed cases.
After consulting with the government, bosses at the factory have now made the decision to pause production from the end of Friday.
The move will allow all staff who have been working at the site to self-isolate as a precautionary measure, while production will be moved to other Greencore factories for the time being.
The factory will undergo a "very significant" deep clean over the next fortnight.
“Greencore can confirm that, in consultation with the Department of Health & Social Care, Public Health England and other government bodies, it has taken the decision to temporarily cease production at its Northampton facility from the end of today as a result of the ongoing COVID-19 outbreak in the Northampton area and at the site," a Greencore spokesperson said.
"This decision will allow all remaining colleagues at the site to self-isolate as a precautionary measure, and has been taken as part of the region’s ongoing efforts to reduce the spread of the virus and keep our colleagues safe.
"We have been in constant contact with PHE East Midlands, Northamptonshire County Council, Northampton Borough Council and other government bodies, who have been hugely understanding and supportive of our response. We will continue to work closely with them in order to bring the site back safely into production as soon as possible, as colleagues who are self-isolating begin to return."
The news comes on the same day that Northampton was added to the government's coronavirus watchlist as an "Area of Intervention".
It was previously named as an "Area of Concern" but has now been escalated to the next level following a steady increase in cases over the last six weeks.
Some 334 new cases were recorded in Northamptonshire in the week to 16 August, up 118% on the week before.
The incidence rate hit 125.1 per 100,000 people during the same week.
The infection rate in the town still remains high, and currently stands at 78.4 cases per 100,000 people.
That figure almost puts it on a par with Oldham in Greater Manchester where further restrictions were put into force on Friday.
Director of Public Health at Northamptonshire County Council Lucy Wightman said the spike in Northampton was almost entirely down to the outbreak at Greencore and employees and "their direct households" would now have to stay at home for two weeks.
“Northampton borough has been experiencing a high number of cases over the last four weeks and from today will be added to the government’s watchlist as an “Area of Intervention," Mrs Wightman said.
“Local testing data shows this spike is significantly influenced by a workplace outbreak at the Greencore Factory.
“I want to thank local people in Northampton for the collective effort to date to help reduce the spread of the virus. We recognise this is tough for everyone but I would urge you all to keep going and to follow the guidance.
"This situation illustrates how fragile our position is, and that if we don’t keep continuing to work together to reduce the transmission of the virus, there is a very real possibility that further and stricter intervention measures and a possible local lockdown will follow.”
A government spokesperson confirmed that any workers from the factory who don't self-isolate for 14 days could face sanctions: "Anyone who leaves isolation prior to the two-week period ending without reasonable excuse will be subject to fines."
Despite the town being singled out as an "Area of Intervention', health bosses say that as things stand there's been no change to the current guidance in Northampton, Kettering, Corby and Wellingborough.
What is the the guidance in Northampton, Kettering, Corby and Wellingborough?
Limit contact with others outside of your household or bubble
Work from home if you can
Keep 2 metres from others at all times, use a face covering where you are less than 2 metres apart
Avoid using public transport or car sharing, wear face coverings if you cannot avoid these
If you have COVID-19 symptoms, stay at home, self-isolate and get a test
Avoid meeting those outside of your household or bubble in an indoor space
Wash your hands regularly and thoroughly for 20 seconds each time
Do not share items with others outside of your household or bubble
If you have COVID-19 symptoms, do not go to work, either work from home or report sick, self-isolate and get a test
Even if you only have mild COVID-19 symptoms, get a test
If you are contacted by test and trace and asked to self-isolate, stay at home for 14 days