This comes off the back of serious efforts by the US to convince its allies to ban the Chinese company from high-speed telecommunications systems due to security risks.
New Zealand has followed the US and joined a raft of other countries in banning Huawei from any involvement in the rollout of 5G technology.
The PM has refused to say whether any Huawei issues have come up through diplomatic channels, or whether there has been any political blowback from China.
However, the findings by the UK now suggest that NZ's ban could have been pre-emptive.
Citing inside sources, the Financial Times reports the British government has now concluded that it can mitigate the risk from using Huawei equipment in 5G networks - a development the paper calls "a serious blow to US efforts to persuade allies to ban the Chinese supplier from high-speed telecommunications systems".
While there has so far been no official announcement, the FT says the UK National Cyber Security Centre (NCSC) has determined that there are ways to limit the risks from using Huawei in future 5G networks.
The UK paper also quotes Robert Hannigan, former head of GCHQ (the Brit equivalent to our GCSB), saying the NCSC had "never found evidence of malicious Chinese state cyber activity through Huawei" and that any "assertions that any Chinese technology in any part of a 5G network represents an unacceptable risk are nonsense".
Spokesman Andrew Pirie says Spark is seeking more information on the apparent UK development.
The telco is still assessing its strategy but maintains hope that a revised Huawei proposal could be given the okay by the GCSB.
"We are still in discussions with GCSB officials," Pirie said this morning as the UK news broke.
"We are working through what possible mitigations we might be able to provide to address the concerns raised by the GCSB, and have not yet made any decision on whether or when we should submit a revised proposal to GCSB."
'Not a ban' - Little
Earlier, GCSB Minister Andrew Little said there was no ban on Huawei per se. Rather, the GCSB vetted telcos' proposed network upgrades on a project-by-project basis.
It was possible that a revised Spark/Huawei proposal could gain GCSB clearance, Little said, if they made technical tweaks that satisfied the security agency.
That stance gives him wiggle room to let Huawei back in without any policy change.
Although the decision to block Huawei from Spark's pending 5G mobile network upgrade coincided with a US campaign to pressure allies to drop the Chinese telco maker - which it alleges colludes with the Chinese government on espionage - Little said NZ made an independent decision.
International security expert Paul Buchanan told the Herald that western intelligence agencies have been right to raise questions about alleged Huawei links to Chinese spy agencies. Huawei has argued that no evidence has ever been tabled, and maintains the allegations are politically motivated.
Growing mistrust
Earlier this month, China's Foreign Ministry spokeswoman Hua Chunying said Huawei's critics are conjuring up threats and misusing state power to "suppress the legitimate development rights and interests of Chinese enterprises" and are "using political means to intervene in the economy."
"All countries should deal with relevant matters in an objective, comprehensive, rational, and correct manner, rather than fabricating excuses of all kinds for one's own pursuit of interest at the cost of others, which is quite hypocritical, immoral, and unfair," Hua said.
It all comes at a time of frosty relations between China and Western countries. And this extends locally, with reports last week alluding to growing mistrust between New Zealand and China.
Massey University's professor Henry Chung, who specialises in international marketing strategies, told the Herald last week that New Zealand faces a big challenge in winning back the hearts and minds of the Chinese consumers.
"There is a sense in China that Huawei has not been treated fairly," Chung said.
As in New Zealand, the concept of fair treatment is important to the Chinese. And the perception New Zealand isn't giving one of its biggest companies a fair go can have a detrimental effect on the willingness of the Chinese to do business with New Zealand.
Adding an additional level of mistrust is the growing awareness of the Five Eyes security alliance, whereby New Zealand, Australia, Canada, the UK, and US share intelligence information.
Chung said reports about the Five Eyes have steadily made their way into the media, sowing seeds of mistrust among Chinese citizens who see those countries as conspiring against them.
Little, the GCSB and Huawei have been approached for comment.
What is 5G?
5G mobile network technology offers more bandwidth than today's 4G networks, allowing more people (or gadgets) to connect to a cell tower and at much faster speeds.
The exact increase in bandwidth is a bit "how long is a piece of string?" because, as with 4G, it will depend on how many other people are on the network at the same time, distance from the nearest cell site and other factors. But 5G should make it easier for telcos to offer true unlimited mobile data plans.
5G also has far les of the lag (or slight connection delay) of 4G in a two-way mobile connection, such as a video conference or online gaming session, making it more competitive with fibre.
Our government will have to auction 5G spectrum before Spark, Vodafone and 2degrees can upgrade their mobile networks to 5G.
It's yet to give a timetable, but says the auction will be in time for early 2020 rollouts.
To take advantage of a 5G connection, you need a phone that supports the technology. Apple, Samsung and other smartphone makers have yet to add 5G as a feature, but are expected to incorporate the technology into new models over the next year or so.
The Telecommunications (Interception Capability and Security) Act 2013, or "Ticsa" requires network operators to run proposed upgrades past the GCSB for clearance.
