Re: This is a Real national security problem. Think hard, Brits!
If you're transmitting information over a phone line, whether that's a landline, or mobile, then you have to assume that your communication might be compromised if you're not using suitable encryption.
Us Brits have long known that the government has the means to eavesdrop on pretty much all of our communications, so we behave accordingly. Equally, I'm sure that the security services don't trust any communications equipment, even if it was built by the GPO.
If we used Cisco instead of Huawei then chances are it would be the NSA listening in instead of the Chinese. So given that there's not much difference either way, we might as well buy from the company that sells better equipment for cheaper.