Following a vote in favour of industrial action, warehouse staff and drivers at 20 Asda distribution depots will stage a five-day strike commencing on 30 June, the GMB union said yesterday (22 June).

Union bosses have said that the strike threatens to disrupt supplies to stores at the UK unit of Wal-Mart during the height of the FIFA World Cup, when grocery spending peaks.

The move is designed to pressure Asda into giving greater union representation at its depots, the union said. "There appears to be a clear clash of cultures between the way workers do business in Britain and the way Wal-Mart does business," GMB National Secretary Phil Davies said in a statement. 

However, Asda has said that it does not anticipate the strike to have a significant impact on the day-to-day running of the stores.

"Around two thirds of our depot colleagues aren't even members of the GMB, and we expect most of them will want to turn up for work as normal. As we've said all along we'll work hard to ensure they can and that our customers don't notice a thing," the company said.