Description:The knocks just keep coming for Barclays. It's to set aside an extra 1 billion pounds for charges and compensation relating to the mis-selling of insurance to customers. The Payment Protection Insurance scandal alone has cost UK banks over 12 billion pounds and could end up more than double that. It comes as the bank's bosses came face to face with the UK banking inquiry. The probe was launched after Barclays was fined 450 million dollars for rigging Libor interest rates.(1:38)