Pressure is mounting on Telstra ahead of an expected appearance by chief executive Vicki Brady, with politicians from both sides of politics demanding answers over the nationwide outage that disrupted mobile services, affected triple-0 calls and caused widespread transport delays across Australia.

Ms Brady has reportedly returned to Sydney after cutting short an overseas holiday following the outage, but Telstra has not confirmed when she will publicly address the crisis.

Her expected appearance comes as scrutiny intensifies over how the outage unfolded and what the company will do to prevent a repeat.

Former deputy prime minister Wayne Swan was critical of the telecommunications giant’s corporate leadership, saying they needed to be financially penalised.

“There’s no question the bonuses of all the executives will be on the line,” he told Nine’s Today program.

“I’m sure the public will want to see a fair bit of accountability.”

Opposition Leader Angus Taylor accused the Albanese Government of failing to provide leadership during the outage, saying Australians were left without information as the disruption unfolded.

“There was no Anthony Albanese to be seen. There was no minister to be seen. They hadn’t explained what was going on. Australians were left in a vacuum,” he told Sunrise on Friday.

Mr Taylor said the government appeared more focused on politics than responding to the unfolding crisis.

“This is a government that sent people out doing political briefings before you’d even had the minister or the Prime Minister out,” he said.

“That’s not about dealing with the issue. It’s all about political spin.”

While stopping short of calling for financial penalties against Telstra, Mr Taylor said there were “serious questions” the company needed to answer, including whether customers and businesses left out of pocket should receive compensation.

“There are serious questions to ask about why this happened,” he said.

“Telstra’s CEO was on a holiday, it’s fine, she’s allowed to go on holidays, but there was no response for many, many hours.”

Asked what he would have done differently, Mr Taylor said his first priority would have been seeking immediate answers from the telecommunications giant.

“The first thing I’d be doing is in with Telstra saying, ‘How did this happen, and what are you going to do about preventing it ever happening again?’ I would have been doing that in the first hour.”

The government has also increased pressure on the telco, with Foreign Minister Penny Wong saying Australians expected critical communications infrastructure to remain operational.

“Telstra certainly has let the Australian community down,” Senator Wong said.

She confirmed the Australian Communications and Media Authority would conduct a full investigation into the outage and said the disruption to Triple-0 services was of particular concern.

“We do expect, particularly our triple-0 network, to remain functional,” she said.

“The fact that there were outages on that network is of deep concern to the community, as well as to the government, and Telstra should be accountable for that.”

Senator Wong declined to comment on reports South Australian police were investigating whether a death at a regional hospital may have been linked to the outage, saying it was important the investigation proceed without political interference.

“I’ll await the outcome of that investigation, but I do pass on my sympathy to the family and friends,” she said.

The political pressure comes after Telstra revealed the outage was caused by a software fault rather than a cyber attack, with chief financial officer Michael Ackland saying the company had also identified a secondary issue affecting some triple-0 calls after the main outage had been restored.

The disruption prompted hundreds of welfare checks across the country after unsuccessful emergency calls, while rail services in New South Wales and Victoria continued to be affected into Thursday.

Attention is now firmly turning to Ms Brady, who is expected to face questions over how Australia’s largest telecommunications provider suffered one of its most significant outages in years, whether customers will be compensated and what changes will be made to restore confidence in the network.