The GMB union will send out ballot papers next week to members, asking depot workers to vote on strike action or other measures, in support of the union's demand for national collective bargaining rights. The results are due back on June 19.
The grocer is waiting to see which way the ballot will go, with results due back on June 19, but if GMB members vote for a strike it will be ready. A spokeswoman said there are 'contingency plans in place,' but was unwilling to give details.
'We will make it easy for those people who want to work to come to work,' she said.
The Union said it remained open to discussions with Asda but, because there was no contact at the moment, strike action looked likely.
'We expect a strong 'yes' vote,' said Jude Brimble, GMB national officer for members working in Asda Wal-Mart.
The GMB and Asda have been at loggerheads since February. The union described the supermarket's proposals as 'unworkable', while the grocer argues the proposed strike is 'unjustified'.
Asda gives full recognition and collective bargaining rights to workers in nine out of 20 depots.
'They are not going to lose recognition in those nine depots,' said the store group's spokeswoman.
She explained the company position on the other depots: if 10 per cent of the workforce were members of a union, the company would allow all workers in the depot to vote either in favour or against collective bargaining.
In at least one depot there are only a couple of GMB members, she said.
One-third of Asda's workforce are members of the GMB, but the strike ballot will not include GMB workers in Asda stores.
Asda refuted the GMB's suggestion that the grocer's stance on unionisation has changed since its takeover by Wal-Mart.