AT&T is bracing for handset shortages across the US and carriers in the UK and France are already dealing with supply disruption and could run out of some popular models, people familiar with the matter said.

British network operators may even resort to using stockpiles of phones they'd built up in case of a Brexit-related supply crunch, said one of the people, a company executive who asked not to be identified as the information is private.

The supply chain chaos may last only a few weeks, but it's already wiping out the smartphone industry's hopes for sales growth this year. Worldwide device sales are set to fall 4.3 percent  in 2020, with European sales tumbling 7.4 percent. 

Number crunchers at consultancy Canalys is forecasting global growth of 3.6 per cent before the virus brought much of Chinese industry to a juddering halt.

"There's a huge supply-side shortage for smartphones that we are already starting to see trickle through to some markets around the world", said Ben Stanton, head of devices research for Europe, Middle East and Africa at Canalys.