Asda employees are being balloted over whether to strike in a dispute over pay.
GMB Union said it is making the move because bosses "refuse to increase retail workers basic pay of £10.10 per hour in line with the other 'big four'".
The ballot, which will close on December 4, comes after the Financial Times reported the billionaire Issa brothers, who co-own the supermarket giant, borrowed tens of millions of euros interest-free from their Lancashire-headquartered petrol station empire EG Group to buy two private jets.
