Staff at the Norwich factory that produces Colman's mustard will walk out on strike on Tuesday over a pay dispute, unions have warned.

Eastern Daily Press: Colman's mustard. Picture: DENISE BRADLEYColman's mustard. Picture: DENISE BRADLEY (Image: Archant)

Stuart Fegan, GMB national officer, said there would be a visible presence of workers at the factory gates of Unilever's Carrow Works site in Bracondale, by the County Hall roundabout, from 6am.

Industrial action is planned for 24 hours, and Mr Fegan added that if the company did not settle the dispute quickly then escalation of action by members would be inevitable.

Unilever has rejected a claim by GMB and Unite members' for an increase in pay in line with the average pay settlement for manufacturing groups across the UK in 2015 (2.4%).

Industrial action follows a recently published report by Unilever chief executive officer Paul Polman showing the company achieved underlying sales growth of 4.7% and 8.3% in emerging markets in the first quarter of 2016.

Further compounding the dispute, the quarterly dividend for shared holders was raised by 6% with Paul Polman himself last year being awarded a pay increase of 24% plus shares, GMB added.

'It is obviously disappointing that our members feel the need to undertake this lawful industrial action for their modest pay claim to be met by the company,' said Mr Fegan. 'GMB fears that if the company does not settle this dispute quickly then escalation of action by our members will be inevitable.'

A Unilever spokesman said: 'We are disappointed that the trade unions at our Norwich factory have decided not to ballot our employees on our improved pay offer, and instead move straight to industrial action.

'We are confident that our offer delivers a package of pay and benefits that is both competitive and appropriate, and we remain open to further discussions with both the GMB and Unite unions.'

Colman's was founded in Norwich in 1814 and as such is the oldest brand in the Unilever portfolio.