Libra has faced fierce criticism from multiple governments and financial experts over its lack of regulation. Facebook was questioned by the US Congress in July for two days over Libra's intentions, and its chief executive Mark Zuckerberg is due to testify at a congressional hearing about Libra on Wednesday 23 October.

Today is meant to be the first meeting of the Libra Association - the group Facebook created to develop the virtual currency- but only one payment processing firm remains in its network.

"There's no two ways about it, it's a huge blow," Charlotte Jee, reporter at MIT Technology Review told BBC Radio 4's Today programme.

"Apparently part of the reason these partners have pulled out is also because Mark Zuckerberg himself is also going to appear on the 23rd in front of the House Committee and we will see what he has to say.

"[Libra] is damaged but still going to be continuing, just perhaps in a different form."