In a reply to TasICT, federal opposition communications spokesman Malcolm Turnbull pledged to honour existing contracts.

"The alternative would be to breach them and that is a course we would not countenance," Mr Turnbull wrote.

TasICT executive officer Dean Winter wrote to Mr Turnbull seeking clarification after the Coalition announced its broadband policy, which relies on existing copper with slower download and upload speeds than Labor's fibre optic to all Tasmanian homes plan.

However, Mr Turnbull said he did not know if contracts for the remainder of the rollout in the state had been signed and pointed out the pace of the rollout had been very slow with just 1900 properties passed in the nine months to April.

"At that rate the completion of the rollout in Tasmania would take many decades, about 80 years by my rough calculation. Be careful what you wish for!" he wrote.

Despite Mr Turnbull's warning, Mr Winter said he was satisfied the NBN rollout in Tasmania would continue as planned, irrespective of the federal election result.

"Tasmania is assured now to be the first jurisdiction fully connected to the NBN and may end up being the only jurisdiction to boast the full fibre to the premises rollout," Mr Winter said.

Premier Lara Giddings said she was still waiting for a reply to her letter to Mr Turnbull sent more than a month ago.

Ms Giddings said she took no comfort from Mr Turnbull's response to TasICT.

"Mr Turnbull appears to be casting doubt on the fact that the entire rollout of the NBN in Tasmania has already been contracted to VisionStream," Ms Giddings said.

"The reality is that government- owned businesses like NBN Co are not able to enter into contracts that bind future governments.

"Therefore, it is highly likely that the current VisionStream contract would have an exit clause.

"This would allow the Coalition to honour the contract without committing to the current rollout."