Labor's credibility on NBN shattered: Libs THE federal government's credibility on the NBN is shot following reports NBN Co has discovered a $5 billion blowout in its construction costs, the opposition claims. NBN Co chief operating officer Ralph Steffens briefed senior executives at the company about the surprise construction cost increase on Thursday, the Australian Financial Review reports. The paper said the $5 billion hole in the construction costs was partly caused by contractors demanding more money. Opposition communications spokesman Malcolm Turnbull said the federal government had been claiming for weeks the NBN was on time and on budget. "Anthony Albanese and Kevin Rudd's credibility on the NBN has been completely shattered," he told reporters in Sydney. (Their) claims are clearly false. It has been blown apart. Mr Turnbull said it was hard to believe that Mr Steffens had not told Mr Albanese about the blowout before telling his executives. He said Labor should have "fessed up" about the project's bad shape. The minister should reveal this. The lack of transparency on the NBN has been shocking. He also rejected Mr Steffens' reported claims that with re-structuring, the cost blowout could be saved. Do you really believe the management that until yesterday was saying everything was hunky-dory and fine is going to be able to make up for this massive blowout? Mr Turnbull said. Mr Turnbull also put to rest "Labor's NBN lies," including that it will be free for taxpayers and that the coalitions will disconnect it and fail to honour the NBN's contracts.