The Competitive Carriers Coalition has slammed advice from former NBN Co management that it should not acquire Telstra's copper network for its alternative fibre-to-the-node plan.

The Coalition, which represents the interests of non-dominant telecommunications carriers in promoting policy and regulatory reform to create an open, competitive market, said the advice to 'rent' the copper network was completely contrary to the principle of structural separation that was at the heart of the case for the NBN.

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An NBN analysis of the government's broadband policy warned it could be left with more than $1 billion in annual maintenance costs if it purchased Telstra's copper network as part of its FttN plan.

A CCC spokesman said it was highly alarming that the previous NBN CO management would disregard the bi-partisan commitment to structural separation and most recently affirmed by Minister Turnbull at a recent industry NBN event.

"Such an arrangement would make NBN Co. a Telstra reseller, and make claims of structural reform nonsense," he said.

"The NBN represents a once in a generation opportunity to break with the structurally uncompetitive arrangements that have bedevilled the communications industry and consumers for 30 years."

The advice was presented in a document written by NBN Co's former management which was given to communications minister, Malcolm Turnbull, as part of the department's incoming briefing following the election.

The NBN Co staff which produced the report have since been replaced with a number of former Telstra executives.

A spokesman for CCC said it had published principles that it believed should guide the future NBN arrangements and maintaining structural separation is at the top of this list.

"Any proposal that NBN Co. buy so called managed services from Telstra would represent an abrogation of NBN Co.'s responsibilities to deliver these profound structural changes," he said.

"The costs associated with the maintenance and operation of the copper need to be assumed by NBN Co and should be reflected in the price, not flick-passed at the expense of genuine reform.

"If the reports today are true, it is deeply disappointing that the former management of NBN Co had so little regard for the views of the organisations it was created to service, and the cause of genuine competition."