Where is Huawei banned from working on critical networks?

Several countries have rejected Chinese telecoms firm over national security fears

• 'Companies are seldom treated like this': how Huawei fought back

Politicians in the US have alleged that Huawei's forthcoming 5G mobile phone networks could be hacked by Chinese spies to eavesdrop on sensitive phone calls, gain access to counter-terrorist operations - and potentially even kill targets by crashing driverless cars. Allies who allow Huawei technology inside their 5G networks have been told they may be frozen out of US intelligence sharing.

Related: US government is 'ignorant of technology', say Huawei bosses