Negotiations between DHL Supply Chain and its workers in Liverpool have collapsed.
Strikes began on 19 December, but further planned strike days were called off after DHL promised to make a "significantly improved offer".
The workforce of 120 on the Burton Biscuits and AB World Foods delivery contract are fighting low pay and victimisation.
Warehouse operatives were set to be paid just 2.5p above the minimum wage when the rate is increased to £8.91 in April.
DHL undertakes the delivery contract for Burton biscuits which includes brands such as Wagon Wheels, Jammie Dodgers, the Patak curry range and the Blue Dragon Chinese food range.
Negotiations took place last week but DHL reneged on its promises and offered no significant increase.
According to the Unite union, DHL offered a rise of less than the cost of half a packet of Jammie Dodgers per hour.
Workers will now return to the picket lines—striking on Wednesday 20 and Thursday 21 January as previously planned.
Further dates have been announced for 2, 3, 4, 5, 8 and 9 February, and additional dates are being considered.
Unite regional officer Kenny Rowe said, “This is an extremely lucrative contract, yet our members are being asked to survive on poverty rates of pay.
“Throughout the dispute, the way that DHL management has sought to demonise workers taking legal strike action has been deplorable and has dramatically increased industrial tensions.
“Strikes will continue unless DHL makes a significantly improved pay offer.”