"I give you my 100 per cent assurance that if you go with the statement along the lines we've talked about, I will never badmouth you in relation to this - privately, publicly, in background, off the record in any way," Bridges says on the recording, which was obtained by MediaWorks.
"I will do everything within my power to keep the things we talked about last week out of the public [inaudible]. I will do everything."
Bridges and Bennett state repeatedly that they are concerned about Ross' mental health - and tell him if he follows their instructions he could return to Parliament next year - and he might even be promoted.
On the tape Bennett suggests citing medical reasons for Ross taking leave as it would reduce interest form the media.
"So it would be for medical reasons?" Ross asks.
"Is that what you want?" Bennett replies.
"I think either medical or family."
"Medical is true," Ross says.
"That's right," Bridges says. "There's no shame in that."
Bennett: "And it means everyone will back off you too - the media and all that sort of stuff."
The new tape also confirms that Bridges and Bennett had raised Ross' treatment of female employees with him. Ross asked for more details but Bennett does not elaborate.
"You haven't even told me what I've supposedly done," Ross says.
Bennett replies: "Simon told you all about the disloyalty stuff Jami-Lee, and quite frankly if that was put to caucus, that would be enough."
Ross rejects any suggestion of harassing staff: "That is the worst. I don't even know what that is," he says on the tape.
Ross subsequently went on medical leave and was later identified by an inquiry as the chief suspect for leaking Bridges' travel expenses.
The Botany MP has been expelled from the National Party but plans to return to Parliament as an independent MP.
He remains on sick leave after suffering a breakdown.
Bridges told Newstalk ZB he believes he did the right thing by not publicly disclosing the harassment allegations against Ross.
"It was always going to be the case given the health issues that I would never be able to talk about it openly.
"What happened was, we were dealing with a very serious, complex matter and balancing and factoring in allegations of inappropriate and disruptive conduct with very serious health matters and I feel certain we got this right for all concerned.
"I know that we were acting in accordance with the women's interests and what they wanted, but I had to also balance a situation where the person concerned had very serious health issues and we were getting specialist advice on how to do with that.
"I did the right thing here. I was trying to act with immediacy whilst also being clear that we couldn't have Jami-Lee Ross in the workplace and he needed time to get well on leave."
Bridges said he has made it clear he regretted saying the reason for Ross' leave was "embarrassing".
He rejected that he had prioritised the reputation of the party over the serious allegations.
"It was about insuring we had a good workplace and insuring that someone with the issues that were there went on leave."