The Food and Allied Workers Union (Fawu) on Friday handed a memorandum to the City of Cape Town, calling for Oceana to continue operating in Hout Bay.
A total of 98 shore-based staff could lose their jobs by a decision to close down the Lucky Star Fish meal facility.
Approximately 200 members of the union handed over the memorandum at the Civic Centre in Cape Town.
In Fawu's memorandum to Oceana CEO Francois Kuttel and the City it said that accusations of violations by Oceana stemmed from complaints by a "small minority" of residents.
According to Fawu "recently residing residents" had a vested interest in "gentrifying" the poor out of Hout Bay.
A group of Hout Bay residents, called Fresh Air for Hout Bay (FAHB), have laid official complaints of odour emissions by the Oceana operation.
In a statement on its website the FAHB claimed that it "has never supported the idea of the factory closing, but rather that the odour be eliminated, believing it negatively impacts life in the community and does not contribute to creating a positive environment for anyone".
The memorandum, signed by Fawu general secretary Katishi Masemola, demanded that Oceana "immediately cease continuing with its threat to close its operation".
Fawu and Oceana should also be allowed to "jointly engage" with the City and the Department of Public Works on the "7 000% rental increase" the company has to pay to continue its operation, the union demanded.
According to Oceana, it had implemented several measures to reduce the smell, including the use of odour abatement technology and the reduction of its normal annual production by 60% over the past three years.
The measures had a significant negative impact on the financial viability of the business, Oceana spokesperson Bulelwa Nombutuma told Fin24.