Around 150 workers gathered out the front of McCain’s Wendouree site on Wednesday afternoon as industrial action stretches into a third week.
Workers will be presented with the new enterprise bargaining agreement on Thursday, however they pledged to denounce the offer by a show of hands at the rally.
Employees also voted to stage further action on Monday.
Workers were joined by a giant inflatable rat which had been brought from the Carlton United Breweries picket line in Abbotsford.
McCain and the Australian Manufacturing Workers’ Union have been in consultation since May.
Plant manager Karl Thin said while it was disappointing industrial action was continuing, the company was confident workers would accept the deal.