According to the trade union, over 500 workers are demanding increased pay, with walkouts from the manufacturer’s Manton Wood site in Worksop planned from 11 September until 9 October.
Unite members perform a range of roles at Greencore, including factory line workers, quality controllers, store workers and cleaners.
Many of the workers earnt “as little as £10.53 an hour” and had been left “with no choice but to head to the picket line” following Greencore’s failure to make an improved offer, it said.
The manufacturer supplies sandwiches and ready meals to retailers including Morrisons, Asda, Aldi, Lidl, Co-op and Boots.
“Greencore workers do difficult work to ensure sandwiches reach supermarket shelves across the country,” said Unite general secretary Sharon Graham.
“Yet their employer, whilst making substantial profits, sees fit not to share the spoils with its workers.”
“Our members will have the unceasing support of Unite in their fight for improved pay,” Graham added.
A Greencore spokesman said: “Having been in discussions with union representatives regarding pay in respect to colleagues at our Manton Wood site since January, we are disappointed that Greencore’s final pay offer, which we believe to be both strong and competitive, has been rejected by union members on a small turnout.
“We will be undertaking a number of planning and mitigation measures at the site in the coming weeks in order to prevent any disruption to service levels for our customers should potential industrial action take place.
“In parallel, we will continue to liaise with both Unite and our Manton Wood colleagues with the aim of reaching agreement.”