Now in many countries, not only in UK, people open a credit line to buy BTC, because there is a real chance to buy and wait when it goes to the moon again. Due to this, banks are in panic (little bit), but they will not fight against BTC, and there is no point in this. World has a lot of services that accompany the transfer / payment in electronic form.
It is not good idea to buy BTC on a credit, especially if banks have high interest rates. For example, In Russia, standart credit rate is 13-17% per year (in RUB). I have a friend who did such mistake (bought BTC on a credit at rate 18k$ per BTC ) and now he is in panic.