It is feared there will be a shortage of Jacob's Cream Crackers and Twiglets this Christmas as factory workers launch an "indefinite" strike.
Around 120 workers are manning the picket line outside the Jacob's Biscuits factory in Aintree, Merseyside, after downing tools this morning.
The factory had to stop production as a result of the action.
It has sparked fears that British shoppers may not be able to buy Jacob's beloved festive snacks this Christmas.
The GMB Union previously said more than 750 staff at the factory would walk out “every single day" until bosses agreed to negotiate over pay.
National officer Eamon O’Hearn said: “These workers are rightly angry – they put themselves on the line to keep the company going during the pandemic.
“Now they need some help to get them through the cost-of-living crisis, but it’s falling on deaf ears.
“Jacob’s workers will now be on strike 24 hours a day, seven days a week until the company comes back to the negotiating table.”
Pay negotiations have dragged on for more than a year, according to union sources.
It is understood employees have been offered 4.25% rises - even though inflation is running at 10.1%.
Limited industrial action began in September.
The GMB is thought to have asked for a 10% increase so its members’ real wages are not cut.
But the firm, which makes Twiglets and Mini Cheddars 'Nibbles' as well as 14,000 tons of Jacob’s Cream Crackers every year, is said to believe such a hike would be unaffordable.
A spokesperson for Jacob’s parent company, London-based Pladis Global, previously said: "We regret that the GMB has decided to take this course of action, despite all of the efforts we have made to reach an agreement with the union.
"However, we want to reiterate that our door remains open to the GMB for further discussions with their representatives."
Strikers are on rotation shifts to ensure a picket line is present at the factory around the clock.
It comes as commuters prepare for more nightmare journeys as train drivers from 12 operators are set to strike later this month.
Members of Aslef will walk out on November 26 after the union said it was still waiting for a pay offer from the employers, despite talks.
It comes after a long-running dispute over pay.
The 12 companies facing the fresh strike are Avanti West Coast, Chiltern Railways, CrossCountry, East Midlands Railway, Great Western Railway, Greater Anglia, London North Eastern Railway, London Overground, Northern Trains, Southeastern, Transpennine Express, and West Midlands Trains.
