"I thought, 'this is great, it's my turn'," House says, adding she imagined she would soon be able to get a faster, more reliable internet connection.

But four months after she joined up to the network, her faith in the NBN is severely shaken. After several short-term outages (which were quickly fixed by her service provider, Telstra), the Melbourne counsellor was left without internet for 11 days last month due to an NBN outage.

Not only did it mean House couldn't access her emails and entertainment like Netflix, she was unable to use video conferencing for regular professional development sessions. House also rents out her spare room on Airbnb and had to host a guest without the advertised wi-fi.

"I'm in the middle of an international city, what the hell's going on here?" she says. "Now I realise how naive I was, thinking the NBN was amazing."

House is one of the thousands of Australians who have recently lodged a complaint with the Telecommunications Industry Ombudsman (TIO). In the last financial year, the TIO received more than 27,000 complaints about the NBN, which represents a 159 per cent jump on complaints received in 2015-16. Top complaints include "new internet connection delay", "fully usable internet service," and "slow internet data speed".

According to ombudsman Judi Jones: "The increase is somewhat to be expected given the accelerating rollout of the NBN, but is still a concerning trend."

Polling by Essential Research also suggests there is a significant level of dissatisfaction. An October 30 poll of 470people who had an NBN connection found only 52 per cent said they thought the NBN services was better than their previous service in terms of speed and reliability. A further 17 per cent said it was worse, with 28 per cent saying it was "about the same". When asked who was to blame, 39 per cent of those polled named the Turnbull government for their NBN problems, 19 per cent said Labor and 42 per cent didn't know.

NBN: the next big political issue?

While the NBN has bubbled along as a political battleground for years, the number of complaints - and the fact they do not discriminate between city and country - suggests it could be about to boil over. Particularly in the event of an early federal election.

ALP national secretary Noah Carroll says the NBN has "turned the corner" as a political issue. Labor's communications spokeswoman, Michelle Rowland, adds the NBN is "in your face". And that any (truthful) local MP will tell you they are regularly confronted with complaints about the rollout. Rowland - who holds the western Sydney seat of Greenway - has heard stories of small businesses going bust, of streets divided by the quality of their internet access and parents driving their children to McDonalds so they can access wi-fi to do their homework.

For its part, the Coalition is calling for more perspective.

"In the last 18 months, the number of homes connected to the NBN has jumped from one million to more than three million," Communications Minister Mitch Fifield says, adding the number of TIO complaints only equate to about one per cent of connected users (calculating 27,000 complaints out of 2.4 million users as of June 2017).

Fifield points out Labor didn't have to deal with many customer complaints because the NBN had so few customers when it was in government.

The Coalition also argues Labor does not have a leg to stand on when it comes to the NBN, because it set up a scheme that was too expensive and too unrealistic. But Labor is banking on voters seeing the NBN as a Coalition project, given it significantly reshaped it when it won government and has owned the scheme for the past four years.

It is also betting there are many more disgruntled NBN customers than those who eventually find their way to the official TIO complaints system.

The opposition could be on to something here. Essential Media executive director Peter Lewis says fast broadband is no longer seen as a fancy, futuristic add-on but as a utility, akin to water or electricity. He questions whether the NBN is going to be "the" political issue of any upcoming election, but says it feeds into the narrative that the government is "not doing a very good job".

While city customers like House are frustrated by the NBN, problems with the rollout have also been keenly felt in regional areas, where existing internet access is patchier to begin with and the mix of technologies used to deliver the NBN is more complex.

Nationals MP Andrew Broad holds the north-western Victoria seat of Mallee and has a staff member working almost full-time on NBN and mobile issues, which he has previously described as ridiculous. Broad says one of the main issues with the NBN is expectation management, in part due to what people were promised under previous incarnations of the scheme.

"It's not easy because of unrealistic expectations that have been created," he says. "We don't build a four-lane highway to everyone's front door."

Independent Cathy McGowan holds the north-eastern Victoria seat of Indi, where she has found telecommunications (including her moves to fix mobile blackspots) has been an "absolute vote winner".

While she says the NBN is a "huge issue" for regions like Indi, she adds the level of tolerance for NBN issues seems to have has risen over the past year. McGowan says locals still report outages or a lack of service but seem to accept it more: they are just used to it.

A political fight from way back

The NBN has a long and tortured history in Australian politics. When Kevin Rudd announced the NBN in 2009, it was billed by Labor as an "historic act of nation building", comparable to the Snowy Hydro Scheme and the Sydney Harbour Bridge. It was to provide more than 90 per cent of the country with "fibre-to-the-premises" broadband, cost $43 billion, be completed in 2018 and make enough money so the government's stake could be sold by 2023.

The Coalition was immediately sceptical about the lack of detail and overall cost, declaring it a massive waste of money. So, amid cost and time blowouts under Labor, when Tony Abbott became prime minister, with Malcolm Turnbull as his communications minister, in 2013, they downgraded the technology to "fibre-to-the-node" instead of all the way to people's houses or offices.

They promised a rejigged NBN would only cost $30 billion and be done by 2016. But fast-forward to 2017 and NBN now has a price tag of about $50 billion and is not due to by finished until 2020. It is also involves a far greater array of technologies - relying on both wired (copper, optical fibre and hybrid fibre-coaxial) and wireless (satellite and fixed wireless) networks.

Along with the customer complaints and delays to the network, there is continued concern about the dollars surrounding the NBN. In October, a parliamentary committee recommended the government order an independent audit of the long-term assumptions underpinning the NBN's financial projections.

Around the same time, NBN Co chief executive Bill Morrow told Fairfax Media the NBN is losing money each time it connects to a home and believes that unless it is protected from competition from ultra-fast mobile broadband it will never make a profit.

The battlelines from here

Rowland does not currently enjoy the profile of some other Labor frontbenchers, but expect to see more of her in the new year, as Australia heads closer to an election. While she is still relatively new to politics (having first been elected in 2010), she is regarded as a sharp, straight-talking MP who is good at working with other colleagues (useful when the NBN touches everyone's electorates).

Her NBN opponent, Fifield, has been in Parliament since 2004, but communications is his first cabinet gig. This is made even trickier when his predecessor as communications minister is now sitting across the cabinet table as the Prime Minister. As one Coalition MP notes, "[Fifield's] got a difficult task".

You can also expect Labor to devote increasing attention to customers' poor NBN experiences, with the hope of converting this into frustration with the Coalition. Rowland says the government underestimates the NBN as the issue, dismissing the complaints as "teething problems ... they don't get it".

When it comes to developing a concrete election policy, however, Labor will have to be nimble. Even though its initial plan was fibre-to-the-premises, the more the NBN is rolled out, the less scope the party has for making changes.

"Every passing day [the NBN rolls out], it limits what an incoming government can do," Rowland notes.

To counter Labor's approach, the Coalition will continue to argue its scheme will still be cheaper and implemented faster than Labor's plan would have been. Fifield is billing the NBN under the Coalition as "one of the greatest corporate turnaround stories in recent memory".

Privately, the Coalition is also betting jobs and cost of living will ultimately matter more at the ballot box.

But both sides face challenges when it comes to convincing voters that they are best placed to handle the NBN, not least because both have had such a significant hand in its making.