Asda stores face running out of beer, pizzas and snacks during the World Cup if strike action goes ahead across its 20 depots, after talks with unions over working conditions and bonus payments broke down.

The GMB union will deliver formal notification of a strike ballot to Asda next week. Any strike is likely to lead to a head-on clash with the football tournament, which starts on June 9, with England's opening game the day after, impacting supply during the biggest event of the year.

The union had been planning to ballot for strike action last month, but called it off, believing it had struck a deal with Asda for individual collective bargaining agreements in each of its 20 depots.

However, Asda has now said that the union misinterpreted the meeting, which the union believed was for the nine of its depots that have union recognition. A GMB spokesman said it represented back-tracking by Asda following president Andy Bond's visit to Wal-Mart in the US. "Why would we call off a strike for something we already had?" he asked.

An Asda spokesman said it would not let a strike affect its stores. "If the GMB does persist with industrial action, we will be working overtime to make sure our customers don't notice a thing when they visit our stores."

Asda people director for policy Caroline Massingham added: "We think our colleagues deserve better than to be wrapped up in a 1970s-style bargaining dispute. If the GMB is serious about dialogue, it has only to pick up the phone."