A recent comment on this site suggests it's “it is illegal to sell goods at different prices depending on the payment method used” in the UK. Yet, all low-cost airlines in Europe seem to do it. In particular, I am frequently flying with EasyJet (out of continental Europe) and I think they are UK-based so presumably bound by this rule.
If that is correct, how does that work? Is there an exception for services or online sales? Are they just blatantly breaking the law?