In a submission to the Australian Competition and Consumer Commission's (ACCC) on , the company suggested Telstra would use its control to favour its own retail business unit to impede competition.

"There is potential for both Telstra and NBN Co to engage in discrimination in relation to facilities access, including Telstra's ducts where space is frequently scarce," the submission reads. "Telstra's past and current practices strongly suggest that Telstra will use its control of this infrastructure to impede competition."

According to the wholesaler, Telstra's duct charges are "excessive" but continue due to the lack of an alternative.

Despite Telstra currently being required to provide carriers with access under the Telecommunications Act, Vocus alleges that Telstra's ownership of the network places it at an advantage and summaries of its deal with NBN Co have been insufficient in explaining the details of the ducts' future use.

"Telstra's duct lease to NBN Co is clearly relevant to assessing the likelihood of whether existing carriers will be evicted from Telstra's ducts, though as the deal documents are not public we are uncertain to what extent," the document reads. "Any negative impact on other carriers whereby Telstra demands that a carrier remove its cables to make way for the NBN will depend on the amount of free space in the relevant ducts."