Speaking to The Examiner  yesterday, Mr Turnbull said Tasmania was in a ``very difficult contract position'' with indications main contractor Visionstream might not fulfil its obligations.

 ``The problem in Tasmania with Visionstream, you have heard me say it previously, is that Visionstream is not prepared to perform contract within the terms of that contract, and is asking for more money,'' Mr Turnbull said.

``Clearly it takes two to tango.

``Honouring a contract does not mean writing a blank cheque.''

Mr Turnbull would not say what would happen if Visionstream, which is behind schedule and reportedly over budget, breached its $300 million contract.

A spokeswoman for Visionstream said the company remained committed to completing its contract with NBN Co.

The federal government is awaiting a full report on the project by NBN Co chairman Ziggy Switkowski, to be released on December 2.

Mr Turnbull's comments followed a widespread panic caused by a re-drafting of the NBN Co roll-out maps, which now only show areas where work was completed or physical works had actually begun.

Premier Lara Giddings yesterday put her support behind a Labor Party petition to ``Save Tassie's NBN,'' which lists 56 suburbs and towns as at risk of missing out on the NBN, including most of Launceston.

TasICT chief executive Dean Winter said the revised maps simply provided a more accurate and realistic picture of the roll-out process, and did not mean suburbs that were not listed would never get the NBN.

Mr Winter said he had invited Mr Turnbull to visit Tasmania next month ahead of the release of the Switkowski report, and expected the government to complete the project in Tasmania.

``When he made that commitment back in April, he was making the commitment that he would roll out the full fibre to the premises in Tasmania,'' he said.

``The best for Tasmania is if Visionstream is allowed to complete the construction as planned, if they are given some leeway.''