Asda has an equal pay claimcomparing the (mainly) women shop floor staff with the (mainly) men distribution staff. Asda argued all the way to the Supreme Court that they could not be compared as they work in different establishments. They lost at every level, so the claim is going ahead and will be costly. The other supermarkets have similar claims against them, but not so advanced. I haven't looked at the Clarks position, but if distribution staff (warehouse, not drivers) are having their pay cut to equalise with shopfloor workers, it may have been caused by that and would probably be a valid reason. However Clarks would still have to deal with claims going back over the last 6 years.