Optus announced yesterday it would sue Telstra in the Federal Court for damages in the range of tens of millions of dollars for the price increase.
The legal action will come on the back of a formal notice issued by the nation's competition regulator the Australian Competition and Consumer Commission (ACCC) last week claiming Telstra's December move was uncompetitive.
But while Optus has reacted immediately to the so-called "Part A competition notice", two of the telcos most affected by the price rise, Primus and AAPT, indicated they wouldn't move just yet.
"The position hasn't been finalised. [Legal action] is something that we are examining but no decision has been made on whether to take legal action at this point," a spokesperson for Primus told ZDNet Australia via e-mail.
"AAPT is still pursuing the matter through its own dispute settlement procedures with Telstra," AAPT's head of regulatory affairs David Havyatt said by e-mail.
"We are hoping the competition notice will make Telstra see sense before there is any need for us to take the same action as Optus."
While primarily broadband-focused telco iiNet only had around 71,000 phone services when Telstra increased prices last year, the company has also been vocal on the issue. However iiNet is similarly unlikely to immediately pursue legal action.
iiNet's general manager of regulatory affairs Steve Dalby told ZDNet Australia in a telephone interview late last week his company was cooperating with the ACCC on the issue.
"We've been involved with discussions with the ACCC since around around Christmas I guess, when Telstra made that change to its pricing structure," he said. "We'll continue to help them with their enquiries."
The ACCC's competition notice had forestalled independent legal action under the Trade Practices Act by iiNet and others, Dalby said.
"When the ACCC didn't seem to be taking any action on it, we discussed it with some other members of the industry and we'd started the process going to take our own private case to court to challenge Telstra using the Trade Practices Act," he said.
"Fortunately the ACCC since then has taken up the cudgel and so that private action is on hold."
A Telstra spokeswoman reiterated the company's stance that its prices were "completely fair and justified" and that Optus' price comparisons were misleading.