London appetite for gold bars, coins rises on Brexit nerves

"It seems to have sunk into people's consciousness that Brexit is a real possibility now. All stocks are being bought out in advance of even being shipped," Ross Norman, chief executive of Sharps Pixley said, noting that demand for Britannia coins, which as legal currency are exempt from capital gains tax, had been particularly strong.

"We had a preconception of who the typical gold buyer was, which is male, mature and over 45. The mix of people coming through has completely rebuffed that idea -- they're often much younger, often female."

ATS Bullion, nearby on London's Strand, has also reported a 5-10 percent rise in sales while online gold dealing platform BullionVault.com, whose customers are largely private investors, said the UK is outstripping other regions in terms of demand growth this month.

Growth in its UK customer base has been 59 percent higher in June than the average of the last 12 months, it said, compared to 5 percent higher in the other nine of its top 10 markets.