Top Optus executives are set to be grilled over the telco's disastrous handling of a deadly triple-zero outage, with calls for scrutiny of the emergency phone network.
A joint bid between the Greens and coalition for an inquiry into the September outage, which is linked to three deaths, is expected to pass the Senate on Tuesday.
The minor party wants to put the "blowtorch" on Optus and the communications watchdog's relationship with the telco.
Optus executives might face a probe at Parliament House as early as Monday.
Opposition communications spokeswoman Melissa McIntosh said the triple-zero network needed to examined.
"I want the whole triple-zero ecosystem to be questioned and to be tested, to be prodded, and for people to have reassurance that every part of that process, every part of the business process, contract, everything is investigated," she said.
Liberal senator Sarah Henderson, who will move to set up the inquiry, called on Communications Minister Anika Wells to appear before the sought probe.
A triple-zero custodian will be set up following the passage of legislation in the upper house on Tuesday to increase penalties for breaches to $30 million.
While the Australian Communications and Media Authority has set up its own inquiry into the outage, Senator Henderson said it was "woefully inadequate and riddled with conflicts of interest".
An Optus spokesperson said the company had commissioned an independent review and was co-operating with the communications watchdog.
The minister has meanwhile notified the communications watchdog of an intention to establish a public register of network outages to ensure people are aware in real time.
"Triple zero is a critical public safety system and Australians need confidence that it will be available when they need it," Ms Wells said.