Malcolm Turnbull has directed that Labor's fibre-to-the-premises solution be abandoned in favour of a mixed-technology model, despite the absence of cost-benefit analysis for the Coalition's preferred arrangement.

The federal communications minister has directed NBN Co to adopt the mixed-technology model favoured by the Coalition government for the construction of Australia’s national broadband network, in lieu of the fibre-to-the-premises model which had previously been advocated by the Labor government.

“The government has considered NBN Co Strategic Review’s report of December 12, 2013, and agrees that the NBN rollout should transition from a primarily fibre-to-the-premises model to the ‘optimised multi-technology mix’ the review recommends,” said a revised statement of expectations issued to NBN Co.

A strategic review of the NBN undertaken at the behest of the Coalition last year recommended the adoption of a mixed fibre to the node model, making extensive use of Telstra’s existing copper network to provide connections to homes. This model would be $32 billion cheaper than Labor’s fibre-to-the-premises model, yet result is significantly lower connection speeds .

While the move is in line with the government’s stated intentions with respect to the NBN, Turnbull has come under fire for rushing the adoption of the Coalition’s model without a cost-benefit analysis, when he had previously criticised the same omission by the Labor government when it sought to implement its fibre-to-the-premises plan.

The cost-benefit analysis of the NBN model was announced in September, and is scheduled for release by the middle of this year.

In response to queries about why the government had directed implementation of the new model without waiting for the cost-benefit analysis, Turnbull said that NBN “had got to get it on.”

Turnbull also pointed out that current plan is versatile enough to be amenable to revisions

“We are committed to a CBA [cost-benefit analysis] for NBN,” said Turnbull via Twitter. “If the CBA warrants changes to the SoE [statement of expectations] it can be revised. SoE has been revised several times and will no doubt be revised in future, but am sure flexible approach to tech will always make sense.”