Rogue National MP Jami-Lee Ross has admitted having affairs with two women - one of them an MP - and says there will be "challenging times ahead" in his marriage.

On the day he was expecting to stand down from his Botany seat, the MP is also now vowing to stay in Parliament and dish the dirt from under the political bed-sheets.

Ross has vowed to stay on as an MP in Parliament. Photo / Michael Craig

In an exclusive interview with Newstalk ZB's Heather du Plessis-Allan, Ross admitted extra-marital affairs with an MP and a former employee and issued an apology to his wife Lucy Schwaner - days after saying he was "comfortable with what I have with my wife".

"I owe my wife a huge apology," he told Newstalk ZB. "I've done some things I'm not proud of. I have apologised to her in person and I'm going to continue to apologise to her in person.

"It's going to be some challenging times ahead. It's going to be difficult. And I'm extremely sorry for what I've done."

Ross also responded to allegations from four women of intimidating and bullying behaviour, disputing the way the allegations were presented but apologising for the "hurt" he has caused the women.

Referring to being accused of inappropriate behaviour from a married MP and the revelations of the affairs, he said: "A scab has been picked on the parliamentary personal issues. It has long been a case where personal matters are kept private, but the rules of the game have changed.

"There's a lot of bed-hopping that goes on down in that Parliament. There's a lot of behaviour that a lot of people would want kept secret and has been kept secret until now. But the way in which we now play politics is that we lift the bed-sheets."

He said he had a "long-term" relationship with an MP, who the Herald has chosen not to name, as well as a brief relationship with a former employee.

Ross also played Newstalk ZB another tape of a conversation between himself and leader Simon Bridges, after Bridges had confronted him with allegations.

Bridges can be heard telling Ross: "As I said to you in the text, this is about the National caucus, the National Party. Actually it's also a workplace and there are basics there that as leader I need to ...".

Ross responds: "And one of those basics is, when an accusation is made, the person who is being accused has an opportunity to answer it, and an opportunity to present a defence, and an opportunity to at least assess what is being placed in front of him. You're expecting me just to accept that you've heard things and you've got some evidence, but I'm not able to see that."

Bridges: "I think what would happen, in all honesty Jami-Lee, if I gave you natural justice on these issues, there wouldn't be four or five, it would be 15."

Ross: "I disagree with you. I deserve to see it."

Bridges: "That's not going to happen."

Ross apologised to Howick Local Board deputy chairwoman Katrina Bungard, who accused him of harassment in 2016 when he was drumming up support for his wife to chair the board; Schwaner quit the board when she failed to secure the chair.

"I owe her (Bungard) an apology certainly for the way I treated her after that Howick Local Board issue ... I shouldn't have done that to her," Ross said.

He said he apologised to Bungard during the mediation in 2016, and the matter was swept under the carpet by president Peter Goodfellow and northern regional chairman Andrew Hunt by getting them to sign non-disclosure agreements.

Jami-Lee Ross said there were challenging times ahead. Photo / Michael Craig

Bungard did not blame the party, saying it did what it could at the time.

Goodfellow said of the matter: "Any issues that we were aware of that were raised were dealt with at the time. We have nothing further to add at this time."

Hunt said he was unaware of the extent of Ross' behaviour, including allegations of bullying and harassing a number of women.

Ross previously planned to stand down from his Botany seat today and force a byelection, but now wants to remain in Parliament.

He fired a warning to the party, saying he could also dish the dirt on a lot of the activity that he took part in as chief whip.

"There is a rot in the National Party. People on behalf of the leadership get asked to do things so the leader is kept clean.

"I was asked to help exit Todd Barclay because he was becoming difficult for Bill English. Bill English was kept clean. Paula Bennett was pulling the puppet strings. But recordings about him came out and ended up in the media."

He said he had a number of text messages between himself and John Key about a donation that had become difficult.

"I was asked by John Key to go in and talk to the donor and see if there was something about the Labour Party that we could find out. John Key and I ended up discussing that later on in text messages.

"The National Party has now decided to smear my reputation as much as possible. I simply can't run in a byelection on that basis. I've decided it's more important to continue talking about the National Party."

Asked about the allegations from the four women, Ross said: "I apologise to all four for hurting them ... I dispute the way in which they've been written up and I dispute the way in which many of the details have come out and have been pieced together, but the bottom line is that I haven't been a good husband."

Earlier this week, Ross released a recording and text messages as evidence of what he calls electoral fraud.

Though questions have been raised about whether they point to any illegal activity, Ross stood by his claims and said police would decide if there was anything worth pursuing.

Asked earlier in the week about whether he had had affairs, Ross said personal lives and family were normally left out of politics.

"I'm comfortable with what I have with my wife - if the way in which we're about to play politics, when a political party and the leader is under pressure, if they want to start lifting the bedsheets on everyone that works in that building, you guys and MPs, then I think there'll be a lot of people concerned - even those that are throwing allegations now."

After the interview ran, Ross took to Twitter, suggesting a story by respected journalist Melanie Reid, of the Newsroom website, was handed dirt on him by the National Party because he had spoken out.

"When I spoke out about Simon Bridges and the Electoral Act, I wanted to expose what I felt was unlawful activity, and my being asked to do things I was uncomfortable with. The National Party's response was to give the four complaints to Newsroom.

"This caused the damaged intended when Newsroom ran its story. It's also highlighted the political tactics undertaken when an MP becomes a liability for the Party leader. I used to know - I used to carry out those tactics for the leadership when I was the Party's whip.

"There is serious rot in NZ politics, and the way the National Party undertakes its activity. There is a greater responsibility to continue exposing the National Party's activity and the way the leadership conducts itself.

"I have not submitted a resignation letter to the Speaker. I intended to do that today. I will instead stay on as an MP to continue speaking out about the internal operations of the National Party.

"I will no doubt continue being called a liar by Simon Bridges and the National Party. That's a very good reason to keep telling the truth that I have witnessed firsthand since 2011."

Asked whether Newsroom was a "dirt machine" for the National Party, co-editor Tim Murphy responded: "Hahahahahahahahahaha."