Further strike action will also take place later this month as members of the Unite, Usdaw and GMB unions look set to call strikes on eight sites across the UK for up to 12 days from January 17.
Unite national officer Jennie Formby told FoodManufacture.co.uk that the strikes are now inevitable unless the consumer giant rethinks plans to scrap the firm’s final salary scheme which will cut retirement income for staff by up to 40%.
She said: “The strikes will definitely be going ahead unless Unilever can compromise and sit down and discuss changes to the plans.
"As it stands, Unilever has made it clear that it is not interested in talking and our members are angry that they are not being heard.”
Formby said union representatives had now tried “on numerous occasions” to sit down and talk with the Marmite and PG Tips owner, which was of “great concern” to Unite members.
“It is not quite the way we would expect the firm to behave, especially one that prides itself on having such a strong moral compass,” she added.
As a result of the failed talks, Unilever workers will now head to the capital tomorrow aboard a “battle bus” in a bid to force the firm’s hand over the pension row.
The workers will be directing a message to Unilever shareholders, asking them to remember that this was a firm founded to bring "ethics" into commerce, according to Unite.
Many members of staff are angry that the Unilever is pushing ahead with plans to make changes to its pension scheme that could lead to poorer pensions for more than one third of its employees.
Unite has also labelled the firm “not as clean as you think” and accused it of being a “pension snatcher” ahead of the plans to hold a series of 24 hour strike across eight different sites beginning next week.
The action will begin on January 17 and will come to an end 12 days later on January 29.
Allan Black GMB national officer said: “Strike action at Unilever demonstrates that pensions are not just a matter of concern for public sector workers.
“The concerns are shared by workers in private sector employers like Unilever too. The action also shows that ordinary workers will not stand idly by to watch profitable employers like Unilever jumping on the pension’s robbery bandwagon.”
A Unilever spokesman said: “Whilst we fully respect the right of our employees to protest about the changes we are planning to make to our UK pensions arrangements, we remain deeply concerned by the disproportionate action the trade unions are taking.
This was a tough but necessary choice which reflects the realities of rising life expectancy and increased market volatility. We believe the provision of final salary pensions is a broken model which is no longer appropriate for Unilever.”
It is our responsibility to protect the long-term sustainability and competitiveness of our business, and to do so is in the best interests of our people, he added.
The latest action follows workers at Unilever walking out over the same issue last month in what was the first national strike in the firm’s history.