A new secret recording has emerged of Jami-Lee Ross and Simon Bridges, with the National leader promising his "100 percent assurance" that he will not divulge details of why Ross was to take medical leave from Parliament.

The incomplete recording features Ross talking to Bridges and deputy leader Paula Bennett before the Botany MP took medical leave from Parliament in early October.

The tape confirms Ross' alleged harassment of women was raised during the discussion, as was his alleged disloyalty to the National Party.

During the conversation the trio discuss minimising media coverage of Ross' decision to take medical leave. They also discuss whether to cite medical or family reasons for taking leave.

Bridges also assures Ross that he will not discuss the details - in any forum - of why Ross was absent from Parliament.

"I give you my 100 percent 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 MediaWorks today that he defended his comments on the tape, saying he was dealing with an "incredibly complex situation".

"The inappropriate behaviour, inappropriate conduct and also serious unwellness... we had medical advice... and I feel absolutely sure we did everything right in the circumstances," he said.

Bridges confirmed today that "four or five" women had raised matters about "inappropriate conduct", but he denied they used the word "harassment" with Ross.

"Subsequently we have seen more serious allegations come forward, but we were dealing with these matters in accordance with women's requests and rights, but I wouldn't suggest they were at that higher level."

Bridges denied they had planned to cover anything up, saying they were trying to deal with Ross' health situation.

"I don't accept it was a cover up.

"Given the mental health issues, this was never going to be public.

"I had to balance these things... We were dealing with things in accordance with women's issues... I was balancing those matters, disloyal conduct, with very serious health issues, and on specialist advice. I think in that difficult situation I got it right.

"These were women that came forward, they didn't want to make complaints."

Bridges said Ross' conduct had to be dealt with.

"In terms of conduct – relations with women, disloyal and disruptive conduct at a level where it had to be dealt, we also had conversations with medical specialists – on balancing those things the right thing had to happen, this person going on leave to sort out their wellness issues," he told MediaWorks.