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.
In an exclusive interview with Newstalk ZB's Heather du Plessis-Allan, Ross admitted to 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 New Zealand 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.
In it, Bridges responds to a request from Ross for natural justice.
"Honestly Jami-Lee if I gave you natural justice on these issues it wouldn't be four or five, it would be 15."
Ross apologised to Howick Local Board deputy chair 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.
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 an ended up in the media."
He said he had a number of text messages between him 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."
