One of those who tested positive is the bakers’ union branch secretary for Greencore Northampton, Nicolae Macari.
Mr Macari told the BBC he tested positive on August 4, along with his mother and father – who also work in Greencore – as well as his wife.
He said: “When all of a sudden three or four people are taken off a line because they have tested positive, people are terrified.
“Making sandwiches seems to be a lot more important than anything else. ”
In the past seven days, there have been 70 new confirmed cases in Northampton alone and the infection rate is well above the county rate with 580 cases per 100,000 people.
Northamptonshire County Council Chief Jonathan Nunn said: “A while ago we were at a crossroads.
“Hopefully we’ve taken this route away from a local lockdown, although we have to say at this point that it’s not certain.
“We can see the impact of all the hard work being done by businesses and residents, but it’s still up for grabs and it could go both ways.
“I reiterate my personal responsibility. In some areas we are regulated. When we go to a store, they insist that we wear a mask.
“At work, we are probably well organized. This is what we do outside of these. It’s carpooling, you have to take a bus and remove your mask.
“We really want people to engage in particular, it’s tracking and tracing.
“If you walk into a hotel establishment, if they don’t ask you for their personal details, which will allow them to alert you later, if they don’t ask, they don’t care about you and your loved ones.
“If they ask you and you resist, it is in fact you who are showing a lack of spirit for your loved ones.
“It’s always within our grasp to avoid local lockdown, but we have to keep the pressure on.
“I’m afraid we have to keep our foot on the gas and keep going. We must continue all these initiatives. Whatever you have heard is a good precaution, keep doing it now. ”
Greencore responded to the outbreak by saying he was doing everything possible to keep his colleagues safe.
A spokesperson said: “Due to the growing number of Covid19 cases in the Northampton area, we have made the decision to start proactively testing all colleagues at our Northampton site.
“We can confirm that a number of colleagues have tested positive for the virus and are now self-isolating.
“We work closely with PHE East Midlands, Northamptonshire County Council and Northampton Borough Council, who fully support the checks we have on site.
“In each case, we immediately conducted a contact tracing and asked our potentially affected colleagues to self-isolate.
“All Greencore locations have extensive social distancing measures in place, strict hygiene procedures and regular temperature monitoring, and we are doing everything we can to keep our employees safe.
“As always, the health and well-being of our colleagues is our top priority. “