NBN Co's fibre network will surpass DSL penetration levels after 2015 if the next-generation rollout continues unhindered, according to analyst firm Telsyte.
The firm said that by the end of 2015, NBN Co fibre would hit three million active connections to homes and businesses, putting it on par with DSL tails.
Telsyte predicted that 4.2 million premises would use NBN fibre by 2017; however a change in the political climate could limit connections to 700,000 connections over the same period.
"If the Coalition wins power in 2013, we expect the new government will stall the NBN while it goes through the Productivity Commission and policy reviews for the initial term of government," research consulting director Chris Coughlan said.
"If this happens the market will swing back to DSL and optical fibre will only be connected to around 700,000 premises by the end of 2017."