The NBN is a quite sensitive critter, politically speaking, but to date that's been something that's politically sensitive within Australia. Reports indicate that Huawei may be blocked from bidding on NBN contracts due to concerns over its ties to China. That's a whole different level of politics at play. The decision was apparently made on the grounds of security, with an ABC report stating that the Federal Government's position is one of responsibility to protect the integrity of the NBN and the information carried on it.
That doesn't sit well with former foreign affairs minister Alexander Downer, who now sits on Huawei's Australian board; he's quoted as saying that:
"This whole concept of Huawei being involved in cyber warfare - presumably that would be based on the fact the company comes from China. This is just completely absurd."
The ABC's 7:30 Report is said to be running a feature on the Huawei case tonight; it's certainly not the first time that Huawei's links to the Chinese government have been questioned, with the US and UK governments both notably wary in recent years. Huawei, for its part, has always stated that its businesses are above board; the same ABC article quotes Huawei's Jeremy Mitchell as follows:
"If we were found to do one thing wrong, to have one back door in any of our equipment, our company would fold overnight. So there's no way in the world that we would ever risk that and to be honest I don't know anyone who would argue that the Chinese government would ask us to do that. I think it shows a bit of a lack of understanding of modern China."