The Birds Eye frozen food factory in Grimsby will close on 28 February next year despite talks with unions aimed at saving the site, it has been confirmed.
Birds Eye says there has been no progress in talks with unions
Parent group Unilever said: "We've had talks but no progress has been made."
Unilever announced in October that the plant in Ladysmith Road was to close with the loss of 600 jobs because it was deemed too small to be competitive.
Since then union leaders have mounted a campaign aimed at persuading the food giant to reverse its closure decision.
GMB spokeswoman Sandra Allen said the union had asked the European Works Council to try to exert pressure on Unilever to change its mind.
In October, the union staged a demonstration outside the Tate Modern in London, where Unilever was staging a reception, as part of its campaign to save jobs at the Grimsby site.
In the meantime, talks have been continuing between the company, the union, North East Lincolnshire Council and regional development agency Yorkshire Forward in a bid to ease the blow to the local economy.
Two meetings have taken place between the parties, the second last Wednesday.
"These discussions are still ongoing," a Unilever spokesman added.