Here are some of today's top exchanges from budget estimates.
'We've got public servants ready to answer questions"
Public servants are ready to answer questions ... just not on the main story of the day.
The government's internal negotiations for a net zero commitment has, fairly obviously dominated early sessions of estimates, but especially in the environment and communications committee. Senator Sarah Hanson-Young has continued on from Labor's questioning of Senator Zed Sesleja representing the government: "Is this more like hostage negotiations with Barnaby Joyce?"
Zed replies: "We're happy to answer any questions you have ... If you want to get into the substance of policies, we've got public servants ready to answer those questions, I'm ready to answer those questions. You want to get insight into a government decision that will be announced very soon."
There you have it: public servants are ready and estimates is on.
'Fight club' cabinet just a colloquial reference
Nationals senator Bridget McKenzie earlier referred to cabinet as a "fight club" on Monday morning following net zero discussions in recent weeks.
Labor senator Penny Wong took those comments to Finance Minister Simon Birmingham to see if that was acceptable for a member of cabinet.
According to cabinet rules, cabinet members are not allowed to disagree with cabinet rulings, even if they don't agree with them personally.
He said he saw no issue with it.
"Does cabinet have robust discussions at times? Yes and I would hope that that's what people expect," he said.
"[Senator McKenzie's comment] sounds like a colloquial reference.
"I don't see the hanging offense you're looking for."
'I have at no stage intentionally winked at Senator Birmingham'
Footage of PMC deputy secretary Stephanie Foster appearing to wink at Senator Simon Birmingham during Monday's hearing has emerged, Sarah Basford Canales reports.
Labor senator Penny Wong asked Ms Foster to explain why she winked when answering questions about her knowledge of former attorney-general Christian Porter's anonymous legal funding.
Ms Foster said she categorically denied intentionally winking at the government senator.
"I can say without looking at [the footage] that I have at no stage intentionally winked at Senator Birmingham," she said.
"So it's either capturing me with an eye closing--.
"I can say categorically I have at no stage intentionally winked."
Here's the footage, you be the judge.