There's no reason to be outraged that the Coalition is moving ahead with the NBN before the cost-benefit analysis is completed in the middle of the year, writes Malcolm Turnbull.

Our commitment to completing and having regard to a cost-benefit analysis of the National Broadband Network is undiminished.

I see there has been a lot of commentary in the media, including social media, about the delivery of the latest statement of expectations (SoE) from the Finance Minister and myself to NBN Co on April 8.

The latest SoE gives NBN Co management a high degree of flexibility as to which technologies it uses within a number of constraints, including a public equity capital limit of $29.5 billion, universal provision of at least 25mbps to 100 per cent of premises and at least 50mbps to 90 per cent of fixed-line premises as soon as possible.

NBN Co is instructed to prioritise poorly served areas for upgrade.

Some people have said that it is an outrage this SoE has been delivered prior to the Vertigan panel's completion of the cost-benefit analysis (CBA) of the NBN, due in the middle of the year.

This shows that our critics are still stuck in a Labor government mindset of technology choices being made politically, if not ideologically.

The key focus of the SoE is to deliver a service outcome within a financial constraint. The company is given great flexibility in which technology it uses and where - obviously the more fibre that can be used cost effectively the better.

As I have always said, if time and money were irrelevant you would run fibre everywhere.

The results of the CBA will be very helpful to both the Government and NBN Co and they will certainly influence the rollout, and, if necessary, may cause a revision of the SoE, which I am sure will go through various iterations in the future just as it has in the past. As the SoE states, the Vertigan Panel's "recommendations will be considered by Government, and, if approved, reflected in a further amendment of the statement of expectations."

The pure financial differences between fibre to the premises (FTTP), fibre to the node (FTTN) and hybrid fibre coaxial (HFC) are all set out in the strategic review but it does not consider the economy-wide externalities (if any) that may be associated with making FTTP available. That is a key focus for the Vertigan panel's cost-benefit analysis, and will be taken into account.

The reason for providing the SoE now is simply so that NBN Co has the formal approval from Government for continuing with its move to a multi-technology approach.

Over the next several months we will see the completion of the CBA, the completion of the negotiations with Telstra and the outcome of the technology trials currently under way. The results of all of this work will inform the final mix of technologies.

But it is critical to remember one very big difference between our Government and Labor's on this matter. Labor made a thoroughly political decision to use FTTP for 93 per cent of the country - heedless of the economic consequences.

We on the other hand have committed to universal service levels and have given NBN Co flexibility as to the technology it uses to achieve them.

Malcolm Turnbull is the Federal Member for Wentworth and is the Communications Minister. View his full profile here.