The move has reportedly been sparked by fears that the continued fall in the price of Bitcoin could leave customers in serious and unsustainable debt.

A spokesperson for the banking group told BBC News: “We continually review our products and procedures and this is part of that.”

A similar ban was implemented over the weekend by some of the biggest credit card companies in the US, including Bank of America, Citigroup, JP Morgan, Capital One and Discover.

In a parallel move, Facebook announced that it was banning advertisements that “promote financial products and services that are frequently associated with misleading or deceptive promotional practices, such as binary options, initial coin offerings and cryptocurrency”.

It said the policy is “intentionally broad while we work to better detect deceptive and misleading advertising practices, and enforcement will begin to ramp up across our platforms including Facebook, Audience Network and Instagram”.