Workers at Birmingham's historic HP Sauce factory saw hopes production would remain finally disappear last night after Heinz confirmed its closure with the loss of 120 jobs.
The American food giant told workers at the Aston plant it would close in March, ending a century of sauce-making.
Heinz announced in May it intended to stop making HP in Birmingham and transfer production to Elst, Holland.
Workers used the compulsory three-month consultation period to fight for their jobs.
Last night union bosses said employees were "gutted" at the news and pledged a boycott of HP Sauce and Heinz products.
MP Khalid Mahmood branded the decision "disgraceful" and said MPs would lobby for the removal of the Houses of Parliament from the sauce's label.
"We were trying to keep the plant open, but now we will be concentrating on negotiating the most we can in terms of redundancy packages," said John Jordan, Transport and General Workers Union acting secretary for food. "We will also start acting against the brand. We are convinced we can cause more damage than the £1.5 million they claim they would save closing the plant.
"These are tactics like the Peugeot campaign, but we will be tying up with another British manufacturer who produces what we hope will become another major British brand."
Heinz say the move to Holland will save the company £25 million over ten years.
Options discarded as unviable, included a new factory; Euro and Government grants to upgrade premises; and a restructuring plan by the T&G involving 40 job losses and shift changes.
David Hobin, Heinz vice president, said: "We deeply regret having come to this difficult but necessary decision, which has only been made after careful consideration of alternatives. It is disappointing we have not been able to find an alternative to close the financial gap.
He added: "This difficult decision is no reflection on our employees, who have continued to demonstrate their dedication and hard work."
The bottling of Lea and Perrins Worcestershire sauce will return to Worcester, and a "handful" of jobs will be open there to Aston workers.
Mr Mahmood (Lab Perry Barr) backed the call for a boycott of HP products.
He said grants from Advantage West Midlands, Birmingham City Council and the Department of Trade and Industry, worth £5 million a year, would have saved workers' jobs. "But they chose not to take that on board. They have deliberately used this as an excuse to close the business down because they had already made a bad decision to buy the Elst plant.
"They want customer loyalty, but they have shown no loyalty to the people of Birmingham or the UK.
"We should get all their products out of our kitchens and off supermarket shelves."
He called for the factory, a city landmark, to be made a listed building.
"This would also stop Heinz selling it," he said. "It is part of our history. And with other MPs, I will insist they take the Houses of Parliament logo off the label. It is a Trade Descriptions Act issue."