A "valued" worker at a factory supplying salad for Marks and Spencer has died after contracting coronavirus during an "alarming" rise of Covid-19 cases among staff.

Bakkavor Tilmanstone factory near Dover in Kent is facing calls to shut for a deep clean and carry out mass testing on its workers after it suffered a surge in the number of Covid-19 cases in November.

Some 139 staff were off work amid the outbreak, including 70 who tested positive for Covid-19 and a further 69 were told to self-isolate at home.

The factory is facing criticism by the GMB union after it allegedly only agreed to staff wearing face masks following pressure earlier this year.

Infections more than doubled from 35 in the third week of last month to 79 by the end of the month, according to figures released by the union.

The factory in Kent has been called to shut for a deep clean following an outbreak of the potentially deadly virus among staff
The factory in Kent has been called to shut for a deep clean following an outbreak of the potentially deadly virus among staff

The site - which remains open as it is classed as an essential workplace - is thought to employ more than 800 people but many are office staff who are currently working from home.

Staff on the production lines have continued to work on the factory floor throughout the pandemic as they are classified as key workers.

GMB says anyone forced to self-isolate should still receive full pay for a Covid-related absence and has demanded mass testing to all staff and a deep clean of the site.

There was an "alarming" surge in the number of positive cases at the factory last month

It has now launched a formal collective grievance against Bakkavor, which has 24 factories around Britain and also supplies to other major supermarket chains.

The company was criticised in the summer at one of its other sites at Newark in Nottinghamshire for failing to enforce social distancing and face mask rules.

GMB organiser Frank Macklin said despite 25 per cent of workers being affected either through infection or isolation, Public Health England had not stepped in.

He added: “Bakkavor Tilmanstone Salads had only experienced a few positive cases of Covid-19 before November, but we have now seen the virus sweep through the factory at an alarming rate in just over four weeks.

General street view of factory
Some 139 staff were off work including 70 who tested positive for COVID and a further 69 were told to self-isolate at home.

“Sadly, the factory has now suffered a Covid-19 related fatality. GMB would like to express our deepest sympathies with this employee’s family at this difficult time.

"GMB has requested the facility close to allow mass testing of employees and a deep clean of the factory.

"Once this has been done, the factory can reopen with staff returning safe in the knowledge every step has been taken to ensure they are working in the safest possible environment.

"We also call on Bakkavor Tilmanstone Salads to pay employees their full salary if they have tested positive for Covid-19 or have to self-isolate. No one can survive on Statutory Sick Pay alone.

"GMB has now lodged a formal collective grievance on behalf of our members, as we believe the health and safety of our members has been seriously compromised at the factory."

In response Bakkavor said "stringent safety controls" were in place and staff had also been briefed on travelling safely to and from work.

A spokesman said: "Sadly, one of our colleagues at Bakkavor Salads Tilmanstone has recently passed away after contracting COVID-19.

"At this early point in the investigation there is no evidence that this case was contracted in the workplace."

The firm already had "very high standards of hygiene, extensive safety measures and good manufacturing practice" since the start of the pandemic and had been working with Public Health England since the pandemic began, the spokesman added.

M&S said the supermarket giant has reduced the amount of stock it is taking from the Kent site while the outbreak is being contained.

A spokesman said: “Our thoughts are with the family and friends of this colleague at this sad time.

"Throughout the pandemic, M&S has been working closely with its suppliers to support them following government guidance and PHE advice.

"PHE are satisfied that Bakkavor is working hard to implement Covid-19 secure measures in their workplace and, to help Bakkavor, we have reduced the volume we are taking from the specific site at this time.”

Bakkavor said it has been running its own internal track and trace process, has enforced mask-wearing and reports virus cases to PHE South East.

On the call for mass testing, the spokesman added that the company would support the move if PHE South East called for it.

On sick pay, the firm said anyone off work would receive Statutory Sick Pay, including those who are self-isolating.

The statement added: "It is a tragedy when a valued member of staff dies. Our thoughts are with the family who we are supporting at this sad time."