Argos drivers are threatening to cause “havoc” for customers by going on strike in the run up to Christmas.

Unite said delivery of Christmas gifts could be “severely disrupted” if its members at the Argos national distribution centre proceed to strike for 72 hours over a holiday pay dispute.

But Argos said it had contingency plans in place and pledged there would be no impact on customers.

The dispute between drivers and Wincanton - the logistics company that serves the Argos national distribution centre in Barton-under-Needwood, Staffordshire - is over the calculation of holiday pay.

Unite claims each driver is owed an average of about £700 in holiday pay from the past two years because Wincanton failed to take into account overtime and extra shift payments when making calculations.

Wincanton’s management has offered to backdate the holiday pay from April this year, according to Unite, but the union argues the pay should pay cover “at least the last two years”.

A Unite ballot showed 83% of its driver members at the national distribution centre were in favour of a strike on 20-23 December. This would have a “knock-on” effect on the seven distribution centres supplied by the national facility and impact stores as a result, Unite said.

“The drivers have patiently tried to resolve this matter for over two years. Now they would like the money they are owed in time for Christmas, which is not unreasonable,” said Unite regional officer Rick Coyle.

“It is very difficult to understand why Wincanton has allowed this saga to get out of hand because this strike by our members will cause havoc and mayhem to deliveries to Argos shops in the run up to Christmas.”

But Wincanton said it was “disappointed” by Unite’s threats to strike given that a meeting with ACAS is already taking place tomorrow. The company said its holiday pay system, which takes into account overtime for the first 20 days of annual leave entitlement in each year, “exceeded” its legal obligations.

Argos drivers at the Basildon centre in Essex are also considering strike action over a separate dispute, which involves a disciplinary system relating to “uncontrolled vehicle movements”. The result of the ballot will be announced on 16 December.