Demonstrators have gathered outside the Nissan factory in Sunderland to protest changes to the firm's pension scheme.
Unite the Union is accused the Japanese car maker of showing "disdain and disregard" for workers by closing its defined benefits pension programme.
Around 2,000 employees are affected by the changes. The protests were the first of their kind since the plant opened in 1984.
Unite has called the changes "opportunistic" and say staff stand to loose thousands of pounds from their pensions. It is calling on Nissan to provide compensation for affected employees.