Workers at consumer goods giant Unilever will stage a protest outside the firm's offices today in a worsening dispute over pensions.
The move follows a decision at the weekend to call a series of strikes at factories across the country, for up to 12 days starting on 17 January.
Workers held a one-day strike last year in protest at the ending of Unilever's final salary pension scheme.
Unilever workers from sites at Purfleet, Port Sunlight, Warrington, Leeds, Crumlin, Gloucester, Manchester, Burton-on-Trent and Chester say they are fighting an "unjustified" attack on their pensions.
Unions said the stoppages will hit production of the global giant's leading brands, including Dove, Marmite, PG Tips, Pot Noodle and Hellman's Mayonnaise.
Unite, the GMB and Usdaw say the company's plans to axe the final salary pension scheme will see the retirement income of thousands of staff slashed by up to 40%.
Speaking ahead of the demonstration in London, Unite general secretary Len McCluskey said: "People are fed up to the back teeth of big businesses growing fatter and bigger still, not on hard graft or enterprise, but by hitting the savings plans of their workforce. The Unilever workers are standing up for themselves and they have right, and their unions, on their side.
"This is yet another black mark against the behaviour of FTSE companies. Here we have the 18th richest company in the world dipping into the pension plans of workers in towns across the UK.
"Given that the pensions scheme is funded and healthy, Unilever's raid on the workers' pensions is nothing other than bare-faced greed. Why else is the company refusing to talk to us? It must surely be because it is ashamed about the base nature of this snatch.
"We sincerely hope that the shareholders can talk some sense into this company and at least get them to meet us at Acas."
Allan Black, national officer of the GMB, said: "Unilever need to get the message that profitable companies will not be allowed to walk away from their savings commitments to their loyal workforce."
Black warned of further strikes unless the row is resolved.
Unilever said it was concerned about the "disproportionate" action the trade unions were taking, adding: "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.
"The pension arrangements which we plan to implement in July this year are exceptionally competitive, and were significantly enhanced in a total of 13 different ways as a result of the feedback we received from our employees during the 100-day consultation process.
"It is currently not clear how the dispute with the trade unions will be resolved, but we are continuing to urge our employees who have participated in industrial action to give further objective consideration to the very competitive new arrangements.
"By continuing to offer all of our employees a defined benefit career average pension plan on their earnings up to £48,000, we are offering arrangements which are unavailable at most other companies in the UK."