Bill Shorten has jumped on revelations that National Broadband Network (NBN) chairman Ziggy Switkowski breached the caretaker conventions that dictate how government departments and businesses are to behave in the lead-up to an election, accusing the company responsible for deploying the NBN across Australia of covering up the facts.
"Yet again, NBN are doubling down on the cover-up, the denial," Shorten told reporters in Perth.
"For an otherwise respected businessman, Dr Switkowski, I think this is a shameful breach."
The Labor leader said that if elected, the board positions of NBN would be reviewed, but he stopped short of calling for Switkowski's sacking.
"This is a matter for Mr Turnbull," he said. "He's caught in a bind of his own making.
"On one hand, if he doesn't sack Dr Switkowski or take action, he's condoning a breach of caretaker conventions. If he does, it confirms the game is up in terms of how NBN has been going in the last three years."
The NBN has returned to the election spotlight following the release of a letter from Secretary of the Department of the Prime Minister and Cabinet (PM&C) Martin Parkinson that said he had found an opinion piece by Switkowski to contravene caretaker guidelines, and that NBN had been warned by PM&C that a draft contained partisan sections.
"The Department of Communications and the Arts sought, and received, advice from the Department of the Prime Minister and Cabinet that the publication of the article in that form was not consistent with the established practices associated with the caretaker conventions," Parkinson wrote.
"I understand that view was strongly conveyed to NBN by the Department of Communications and the Arts, as was the view that the conventions apply to the chairman, as well as to the CEO and the company. Our understanding is that this view was passed to Dr Switkowski."
In response, NBN has not backed down, defending the actions of its chairman.
"Any accusation that the company's staff, management, its board and (by implication) its shareholder departments have conspired to keep large cost increases secret from the Australian people is not only plainly and demonstrably false, but is a serious accusation in light of the Corporations Act (for example, section 184)," an NBN spokesperson said.
"This is obviously not acceptable, and the opinion piece addressed the allegations in a manner commensurate with the mode in which they were made; that is, publicly in the national media."
Australian Prime Minister Malcolm Turnbull yesterday called for the politicisation of the National Broadband Network to end, following Labor's announcement pledging to add up to 2 million premises to the fibre-to-the-premises footprint, as well as to retain the use of HFC networks.
Shorten on Wednesday called for the prime minister to show leadership on the Switkowski issue.
"Is the government so addicted to hanging onto power [that] anything goes under a Turnbull administration?" he asked.