The emergence of a confidential NBN Co report – prepared during the caretaker period at the request of the former Department of Broadband, Communications and the Digital Economy (DBCDE) for incoming communications minister Malcolm Turnbull – confirmed long-held concerns that the new government would struggle to keep its NBN election promises.

Delivering 25Mbps to all Australian premises by 2016, as promised in the party's broadband election policy, was "unlikely", according to the report, which was recently obtained by Fairfax Media and ZDNet Australia.

The NBN Co assessment said the government's secondary deadline – the upgrading of 90 percent of premises to 50Mbps speeds by 2019 – "could be achievable" but would slip if the government failed to move quickly to resolve a number of significant issues.

The report, which also said the new government was taking the wrong approach by rolling out its NBN in two stages, suggested a period of "for example 18 months" would be an indicative timeframe for all of the issues to be resolved.

Like the twelve labours of Hercules from Greek mythology, the issues identified in the report are many and complex. Here they are:

"The issues outlined above are likely to impact on NBN Co's ability to achieve volume rollout," the NBN Co report warned. "Subject to the conditions outlined...being completed in a relatively short time frame (for example 18 months), NBN Co considers that a 2019 completion date could be achievable given that time could be saved rolling out an FTTN network compared to an FTTP network."

"However, any significant delays in the preparatory and transition work could delay a 2019 completion."