Tasmanian contractors promised up to six years work on the NBN rollout are demanding compensation if the federal government does not commit to fibre-to-the premises as originally planned.
About half a dozen contractors that invested millions of dollars in specialised equipment for the project rallied in Hobart this morning.
Brighton-based contractor Andrew Bullock said the federal government had broken its pre-election promise to honour existing contracts.
Even if NBN Co adopts an alternative proposal to use Aurora power poles to complete the rollout, Mr Bullock said that won't involve the 60 contractors across the state prepared for the underground work.
Mr Bullock said many contractors were now seeking legal advice.
''You can't get people to invest millions and then leave them high and dry,'' Mr Bullock said.