I remember some talk about it here on FT a while back but didn't realize they actually went ahead with it!
And why are they charging me to use my BA Amex??? Surely they would want to encourage me to use it rather then a switch card.
If you book a flight on BMI they will also charge you for using a credit card rather then a Switch/Solo but they won't charge you for using a BMI Mastercard.
Basically it now costs us a premium to book with a BA flight with a BA Amex how ridicules!!!