A sandwich-making factory at the centre of a coronavirus outbreak has remained partially open despite almost 300 staff testing positive for the virus.
Workers at M&S supplier Greencore in Northampton, say departments including dispatch are still working despite a temporary government closure.
The company said a "small number" of workers were working "in order to monitor and maintain the site".
The local director of public health said some operations could continue.
A deep clean remains in progress.
In all, 287 staff at the factory on Moulton Park Industrial Estate tested positive for the virus and are being instructed to self-isolate.
George Attwall, regional officer for the The Bakers' Union which represents staff at Greencore, said: "People have been saying what about us? We are still working?
"They have previously been travelling in with production workers in the same cars, they have been sharing smoking areas, canteens.
"Some families even work together - husband in dispatch, wife in production."
Earlier this month, Northampton had the highest rate of positive Covid-19 cases in England, although the figure was largely attributed to the outbreak at Greencore.
Northampton's latest seven-day rate is 35.6 cases per 100,000, down from 117.
Director of Public Health Northamptonshire Lucy Wightman said the Department for Health and Social Care had agreed certain parts of the site - including security and its dispatches unit - could continue to operate, provided staff had not returned a positive test for the virus.
"Because the premises [of the factory] are so large, there was a close down phase," she said.
"So there are exclusions to the secretary of state's directive."
She said there was "agreement" that some parts of the operation could continue.
The Greencore outbreak coincided with Northampton being added to a government watchlist as an "Area of Intervention".
Greencore said in a statement: "While production has temporarily ceased at our Northampton facility, a small number of colleagues are still working across a number of functions in order to monitor and maintain the site."