Labor and the Greens are ramping up pressure on the Nick Xenophon Team to not fold to government pressure over media law reforms.
The debate over the embattled legislation is expected to resume in the Senate on Tuesday, with the support of the Xenophon trio of votes crucial for its passage.
"Nick, you can't turn a blind eye to this, you can't wash your hands of this," Labor senator Penny Wong told reporters in Canberra on Tuesday.
"If you sign up to a deal on media reform that you know has as part of that deal an attack on the ABC and SBS then you're responsible."
The sticking point for the legislation's passage is the two-out-of-three media ownership measure, which Labor and the Greens oppose.
The government has won the support of the four One Nation senators conditional on an investigation into the ABC and changes to be made to its charter.
"Nick Xenophon has the opportunity protect the ABC and SBS from One Nation's attack," Senator Wong said.
Greens senator Sarah Hanson-Young said her party were still in discussions with the government over proposed reforms.
For the Greens to support scrapping the two-out-of-three rule it would need to be accompanied by proper mechanisms ensuring media diversity and public broadcaster protections.
"It's a message to other crossbenchers: don't ... cuddle up with One Nation's attack on the ABC just because the government wants to get the two-out-of-three rule through parliament this week," Senator Hanson-Young said.
"It'd be a sad day indeed if crossbenchers line up with One Nation to attack our public broadcasters. The Greens won't be. We'll be defending the ABC and SBS all the way down the line."
The Nick Xenophon Team was contacted for comment.