Workers in the GMB union at Katsouris Fresh Foods, in Wembley, north west London, have organised a mass meeting for Saturday of next week following industrial accidents at the plant.
Two workers have lost fingers there recently.
The meeting will plan a campaign to force Katsouris to improve the safety at its three Park Royal sites.
It is likely to include demonstrations outside major stores such as Tesco, Marks & Spencer, Sainsburys and Waitrose - all of whom are customers of Katsouris.
GMB member Dimple Muit lost the top of the middle finger of her right hand while using a machine that she had reported to be faulty.
Her manager refused to call an ambulance, instead offering her tissues to staunch the flow of blood.
When she was finally taken to hospital by car she was left by herself outside the A&E unit holding a plastic bag containing her finger.
The delay meant that her finger could not be reattached.
Shortly after this Nitin Chokshi suffered an accident at the Katsouris site where the tops of two fingers on his left hand were severed.
The GMB has written to the Health and Safety Executive (HSE) demanding action against the company which has been served with seven HSE improvement notices in recent years.
Hiten Vaidya, a GMB health and safety expert, said, “Getting compensation for people injured by Katsouris is not the point.
“No one should go to work fit and healthy and leave it injured. Both these accidents were avoidable.
“The company has to clean up its health and safety record. It has a duty in law to provide a safe working environment.”
Meeting is at 4pm, Saturday 9 September, Brent Indian Association Community Resource Centre, 116 Ealing Road, Wembley.