ACCAN, which bills itself as Australia's peak body for consumer representation in communications, was responding to queries from iTWire about the concerns raised by the Australian Competition and Consumer Commission around the proposed deal.
Vodafone Hutchison Australia and TPG Telecom announced a merger of equals on 30 August, with the scrip deal creating a company with an enterprise value of about $15 billion.
But on Thursday, the ACCC raised some concerns about the intended deal, saying that a mobile market with three major competitors was likely to have less competition than one with four.
ACCAN's director or policy Una Lawrence told iTWire: "ACCAN supports a telco sector that is competitive and affordable for consumers.
"In order for this to occur, Australia’s telcos sector needs providers that have a strong national footprint, are sustainable in the long-term and can guarantee consumers reliable access to mobile and broadband services.
"The potential merger of TPG and Vodafone must be considered through this lens."
The ACCC said it had published a statement of issues surrounding the proposed merger and had invited submissions from interested parties until 18 January 2019.
"We welcome the ACCC’s further examination into the impact of the merger between TPG and Vodafone," Lawrence said. "We hope that it will ensure that consumers’ interests are at the heart of any final decision."
Contacted for comment, Communications Alliance chief executive John Stanton said he could not comment on commercial issues around carriers, as all were members were of the industry lobby group.
A final decision on the proposed merger will be announced on 28 March 2019.