Hundreds of banner-waving protestors marched through Dover demanding that port jobs are not privatised.
Families were joined by union members, French port workers and MP Gwyn Prosser for the rally on the seafront on Saturday.
The demonstration comes three days before a 48-hour strike is planned by port workers over Dover Harbour Board's plan to transfer 190 jobs to private contractors.
Jane Jeffery, regional organiser for the union Unite, said the strength of feeling in Dover was obvious from the hundreds who supported the protest.
"Workers feel angry and betrayed and are worried about the future of their jobs," she added.
Dover Harbour Board says it intends to keep the port open for business but the volume of freight travelling through Kent on its way to Europe is usually at its peak midweek.
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