Tomorrow's full page adverts in The Mirror and Guardian newspapers mark the beginning of a national campaign encouraging people to boycott Peugeot and Citroen, unless the company meets unions to consider a plan to save production at the plant.
The decision to close the Ryton plant in Coventry was made in April.
The plant will be brought to a close in two stages. It currently operates two shifts, which will be moved to a single shift in July. Production will not continue beyond July next year.
Amicus and the T&G want Peugeot to keep Ryton open on the basis of the survival plan developed by the unions.
The union say they could adopt similar tactics for other companies that chose to cut jobs and plants in the UK and move production to other parts of the world.
Derek Simpson, general secretary of Amicus, said: "Companies that seek to sell in Britain should build in Britain. We believe that the wider British public will want to send a powerful message to companies like Peugeot that are prepared to close profitable and productive plants here in the UK and lay off loyal, skilled and hard working employees and a drop in sales will really hit them where it hurts. We need to draw a line in the sand and say to companies that behave in this way that there will be consequences for their actions."
T&G general secretary Tony Woodley said: "The unions have produced a robust plan which could provide a profitable future for the Ryton plant. Peugeot is motivated by sheer greed and needs to understand that there will be painful consequences if they shut up shop in Britain in this fashion.
"If they refuse to talk, and our members who will still be working at the plant after immediate forthcoming redundancies want our support, we will fund a campaign to make the public aware of this corporate betrayal, and if this hits Peugeot in the wallet, so be it."
The unions are also campaigning for the strengthening of UK labour laws to stop workers here being more vulnerable to redundancy than those on the continent because they have stronger employment protection.