CEO Andy Clarke (the Archbishop of Asda , as Michael Buerk dubbed him at the IGD Convention), can afford to feel just a little bit smug at the moment.

While trading in the EDLP supermarket can’t hold a candle to the EDLP discounters in terms of growth, at least it’s in positive territory, as its early and simple devotion to tackling the price gap to Aldi and Lidl has started to bear fruit.

Unfortunately, other events seem to have a habit of overshadowing Asda’s trading progress. Earlier this year it was his decision to axe 1,360 in-store jobs. Now a dispute involving in-store checkout workers is threatening to do the same again. And this one is not even related to his own actions.

“There’s a third way of looking at the Asda Equal Value case: it’s not about sex, it’s about union power”

Adam Leyland, Editor

Under a directive called Equal Value, introduced by the EU in 2006, if two jobs are similar in scale and impact, it has decreed they should be in the same pay band. A class action lawsuit involving 19,000 checkout staff argues their pay rates should therefore be the same as for a job in one of its DCs.

The debate has been framed as a gender discrimination case in the national media. It’s no such thing: the case rests on whether the work of a checkout assistant - whatever their sex - is the same as that of a worker in a DC.

But there’s a third way of looking at this: it’s not about sex, or work, it’s about union power. In 2006, then-CEO Andy Bond tried to take on supply chain workers. When they threatened to strike - backed by the GMB - Asda caved in. It was a rare failure for Bond in his turnaround of the Walmart-owned retailer. And the GMB went on, two years ago, to use collective bargaining to increase pay and productivity. And from next year, the GMB is expected to win recognition again in Asda.

In the case of shop floor workers, however - represented by Usdaw - the pressure on management has been negligible. Until now. The ambulance-chasing lawyers at Leigh Day have taken up the cudgels on behalf of shop floor workers. And if they win against Asda, the floodgates open: this is a case that will affect every supermarket. In fact, every retailer. So while the spotlight is on Tesco , Morrisons and Sainsbury ’s, it’s also on Asda and Andy Clarke. And he must be wondering: why me?