DHL said any disruption with deliveries to Sainsbury’s stores in the South East would be minimised after staff at its Dartford distribution depot voted for strike action.
The Unite union said more than 350 DHL workers were now poised to stage walkouts in March, April and May in a growing row over the suspension of one of its stewards.
It said disruption could be avoided if DHL revoked the “completely unjustified suspension”.
Unite claimed the steward had been providing support to another worker during an investigation hearing and was suspended for challenging a manager’s version of events.
It said DHL believed the steward was being aggressive.
Phil Silkstone, Unite regional officer, said: “It is clear to our members that DHL’s completely unjustified suspension of a Unite steward is a clear attempt at union busting.
“They are well aware that if the suspension is allowed to stand, it will only encourage attempts to try and weaken collective bargaining, pay and terms and conditions.
“Strikes and the resultant disruption to Sainsbury’s Easter supply chain will go ahead unless DHL revokes the suspension and builds bridges with staff instead of knocking them down.”
A DHL spokeswoman said it was disappointed by the vote in favour of industrial action, but she added: “We look forward to further talks to reach a satisfactory outcome for both parties, but contingency plans are being drawn up and every effort will be made to minimise disruption to deliveries should the action go ahead.”