Unite claims that Thanet Earth the UK's largest greenhouse development uses approximately 80 workers in its packhouse every day who have temporary worker status, some of whom have been there for two years.
"By keeping these workers, employed by agencies, Thanet Earth manages to bypass legislation that would grant them basic protection at work," claimed Mick Duncan, Unite senior regional organiser, South East Region.
To highlight their grievance, Unite held a press stunt last week where Unite officers walked the public footpath that runs across the Thanet Earth site to call on the company to stop "walking all over workers' rights."
Thanet Earth said its reliance on agency labour was in line with the wider food industry and therefore not unusual. "To offer permanent contracts and standard in-house employment support to the majority of our manual workers would greatly increase costs and threaten the economic viability of Thanet Earth," said a spokeswoman.
Although Thanet Earth Marketing (which is responsible for the packhouse operations) had been audited and passed by the relevant enforcement authorities, the company had asked the Gangmasters Licensing Authority to visit the site this week "to challenge the allegations made by Unite," she added.
Unite now plans to take a delegation to lobby local MP Roger Gale this weekend and lobby the local council later this month. It has also spoken to the supermarkets Thanet Earth supplies and has threatened to picket them next month if no progress is made following talks.
Thanet Earth had met with Unite representatives twice, and all concerns raised had been addressed, the Thanet Earth spokeswoman claimed.