Is that actually legal in the UK ? A merchant (which includes airlines, surely) cannot charge a consumer for the use of a credit card over here.
Yes - before Margaret Thatcher, it was illegal!
(Rest of post criticising her decision deleted - bad form to introduce politics to Pprune!)
However, in the USA shops don't show the
total price you have to pay including taxes and service charges. Over here, it is illegal for shops to display a price for an item without the total price, including applicable taxes, being clearly shown. (Shops selling exclusively to VAT registered businesses are allowed to show prices excluding VAT as this amount can be reclaimed.)