Citing new results from the Economic Intelligence Unit's , Turnbull that the NBN is "lunacy" because "no other country around the world is intervening in the private market to the extent to which the Gillard government has".

"Whereas Stephen Conroy is investing only in FTTH [fibre to the home], the rest of the world will invest in competition, affordability and in innovation."

Turnbull said the NBN must be means tested by an independent body before any further development takes place.

"Labor is entitled to argue that it knows better than the rest of the world," he said.

"But it should at least do the responsible thing and have its assumptions tested by an independent body such as the Productivity Commission."