Members of the GMB union at more than 21 Asda depots are balloting on strike action in a dispute over pay and conditions.
Over 300 stores are involved in a consultative ballot over the refusal to pay bonuses.
Bosses have told workers to increase profits from £770 million in 2005 to £825 million for 2006. Asda workers who used to earn above the minimum wage – with bonuses on top – will have their wages lowered to the minimum wage level.
This is despite the fact that every Asda worker produced £5,500 in profits last year. They are now being told to work harder for less money.
The GMB accuses Asda of trying to do away with collective bargaining in depots, and is unhappy about bonuses not being paid.
Asda is owned by the huge Wal-Mart multinational a notorious anti-union firm in the US.
Asda had to pay £850,000 to staff at the Tyne and Wear depot for unlawfully offering them a financial inducement to give up union rights.
The GMB has run a high profile campaign against Asda. Calling strike action can put Asda on the defensive.