Telstra CEO, Andy Penn, has warned high-speed mobile technology (such as 5G) could prove “incredibly damaging” to the National Broadband Network (NBN) – taking customers and earnings.

Speaking to the National Press Club on Wednesday afternoon, Penn warns the over $50 billion project has left itself vulnerable to the next generation of high-speed mobile.

Mr Penn affirms high NBN wholesale prices have rendered it unprofitable for telcos to re-sell – more than doubling in cost since roll-out, and tipped to further rise.

The news comes as both Telstra and rival Optus further progress their 5G roll-out, better catering to the smart home generation with multiple IoT devices.

Mr Penn acknowledges 5G will likely not replace the NBN, however, warns it’s likely to tempt some customers to switch.

An influx of transitioning customers is tipped to hamper NBN earnings, putting further upward pressure on wholesale prices.

Penn has encouraged the government-backed NBN to reduce its pricing, adding it has unnaturally distorted the local broadband market.