The NBN, as the national broadband network project is known, is a story of state intervention, political ambition and a ballooning bill for taxpayers.

Australia's A$49 billion (NZ$54b) broadband network was meant to spearhead a digital revolution. Instead, the botched project risks becoming a poster child for government mismanagement.

The nation's biggest-ever infrastructure investment has turned into a political football, plagued by cost overruns and construction delays.

With the network years behind the original schedule and only about half finished, Australia has slumped to 50th place on a global ladder of internet speeds, behind Kenya and a string of former Soviet bloc nations.

Public frustration with the project is boiling over amid mounting criticism that politics is trumping policy across a host of areas from housing to energy and damaging Australia's economic prospects.

READ MORE: ​New Zealand broadband ranking revealed

The Australian average download speed in the first quarter of 2017 was 11.1Mbps, compared to 14.7Mbps in New Zealand.

"We are really an example of how not to do it," said Paul Budde, a Sydney-based former adviser to the United Nations on the social and economic benefits of digital development. "We have ended up with the worst possible solution."

The network was conceived as a high-speed platform to increase economic output and beam state-of-the-art health and education services to remote corners of the country. The cost of failure would be stark.

With a substandard internet backbone, it's tougher for workers to move from major cities and ease pressure on house prices in Sydney and Melbourne. It becomes harder to boost productivity, which the central bank says must improve to avoid a decline in living standards.

Ian Martin, a telecommunications analyst at New Street Research in Melbourne, says the network will never generate enough revenue to recoup its cost.

"It will never be a success financially, not in terms of ever getting the money back that's been spent on it," said Martin. "To do it as a nationalised government monopoly was clearly the wrong way to go."

The NBN, as the national broadband network project is known, is a story of state intervention, political ambition and a ballooning bill for taxpayers.

POLITICAL FOOTBALL

"The whole thing's been a political football from the start," said John Hewson, who led the Liberals in the early 1990s and is now a professor at Canberra's Australian National University. "The governments are the masters of their own demise on the NBN."

The company is straight-jacketed by the government's insistence on a financial return from the network, even though as a wholesaler NBN can't sell directly to the public and set the final price of a connection.

NBN says it's aiming to increase annual revenue more than five-fold to A$5.4b and be cash flow positive in 2021.

While retailers have complained they're being charged too much to access the network, NBN chief executive Officer Bill Morrow has accused them of a "land grab" for customers while minimising capacity purchases.

That's led to peak-hour crunches that have left many users complaining of dropouts when using streaming services such as Netflix.

As customers switch over to the NBN, frustration with download speeds is boiling over, with complaints to the telecommunications ombudsman more than doubling to 7512 in the second half of 2016 from a year earlier.

NBN argues that complaints rose as more people connected to the network.

Exasperation at a lack of information, coverage holes, service dropouts and delays at being connected were common among the almost 200 public submissions to a 2017 parliamentary inquiry.

DEBATE CENTRED ON THE CHOICE OF TECH

Much of the public debate has centred on the choice of technology, pitting Labor's original fibre-to-the-home proposal versus Turnbull's fibre-to-the-node - where about 40 per cent of homes will rely on copper for the final connection.

Budde, whose career as a telecommunications consultant spans four decades, says the copper network has such a short life expectancy that the government will have to spend billions of dollars next decade upgrading the wires to fibre. Good money after bad, says Budde, who formerly advised Stephen Conroy when he was Labor communications minister overseeing the NBN.

Last week, the Australian parliamentary inquiry's report into the NBN called for an independent audit of the project's business case and recommended that fibre be used where possible for the rest of the rollout.

Fibre internet connections in Asia outnumber any other high-speed alternative more than two to one, while developing nations are also skipping older technologies and opting for fibre, according to a UN agency.

Australia risks missing the next wave of digital innovation as businesses that need faster web connections head overseas, said Matt Barrie, chief executive officer of Freelancer Ltd, the Sydney-based job-outsourcing company that has about 25 million users worldwide.

"They're going to all sprout up and grow in Silicon Valley or across Asia and you literally won't even be able to access the services here, let alone start the companies that provide those services," said Barrie.