Facebook's planned virtual unit Libra, already under heavy attack from US President Donald Trump and global regulators, faces scepticism among the wider cryptocurrency community as well.

One theme - besides Brexit - dominated discussion among the movers and shakers from London's financial technology or FinTech industry as they gathered for their annual get-together: the future of virtual currencies.

"Can I just ask you to raise your hand if you would not be willing to use Libra?" asked the moderator at an event at London's recent FinTech Week.

In the room, filled with about 100 experts and media who closely track the sector, about two-thirds of participants raised their hand to express distrust at the upstart currency.

Helen Disney, founder and boss of Unblocked Events, which promotes the blockchain technology that powers many cryptocurrencies, acknowledged growing doubts over who exactly would oversee and regulate Libra's operation.

People are "concerned about how the governance... would work," Disney told AFP.

"The cryptocurrency community is very libertarian in thinking," its "about giving power to the people, democratization of finance, keeping away from big banks and companies who control [the] economy," she said.

Last week's gathering came one month after Facebook announced to the world its plans for the virtual currency.