National Party leader Judith Collins said changes to the National Party's selection rules will include much stronger vetting of potential candidates' social media histories and more comprehensive reference checks.
The National Party is due to meet later this month to vote on proposed changes to its internal rules after a string of problems with MPs and candidates, and a disastrous election result in 2020.
Last week, there were allegations by an ex-partner of 2020 Upper Harbour candidate Jake Bezzant that Bezzant had impersonated her on social media, including using intimate photos of her.
Bezzant has denied it, saying there were two sides to every story, but Collins was scathing about the reports saying "I thought that was one of the most disgraceful things that I've ever seen in politics and I'm just glad he wasn't an MP".
Collins has pointed to the party's selection processes as being partly to blame – but said she still has confidence in party president Peter Goodfellow: "Yes I do. It's a tough job."
She said there needed to be more "professionalisation" of the candidate vetting process, rather than leaving it to the local electorates.
"I think that today's world with social media it is very important we have people going through social media checking on things. We also have to not just rely on the references and reference checks that people give us in the forms where they apply to be candidates, but we need to wider than that."
It follows problems with MPs including Hamish Walker, Andrew Falloon and Jami Lee Ross over recent years.
Meanwhile, National MP Nick Smith is due to return to Parliament to deliver his valedictory on Thursday: his final day as an MP.
Collins is still refusing to say whether or not it was she who told Smith that an employment inquiry into him had been leaked to the media: something that was the trigger for his decision to resign.
Last week, Smith announced he would resign from Parliament on June 10, saying his timing was partly because of a Parliamentary Service investigation into a "verbal altercation" he had with a staff member last year.
Smith said he had been told details of that had been leaked to the media, and would be published last Tuesday.
Thus far, no media has revealed they were leaked the information. The NZ Herald was told Collins had told others that Newshub's Tova O'Brien had been leaked the story – but on Friday night, O'Brien said she had not been given any such leak.
On her way into the first caucus meeting since Smith's announcement, Collins repeatedly refused to say whether she had misled Smith or told him it had been leaked, saying she would not comment on discussions she had with her caucus colleagues.
Asked if she may have left Smith with the impression that the story was about to hit the media, she said "it's a very long bow to draw, and I will not be going down that track".
Smith has also been quiet on who told him it had been leaked. Since announcing his retirement, the only interview he has done was with the Nelson Mail.
Collins said she would stay in Wellington for his valedictory "and we will obviously want to celebrate his 31 year career with him afterwards".
Asked if there was a bullying problem in National. Collins said every political party has had to wrestle with such issues – pointing to cases such as Meka Whaitiri who was stood down as a minister last term because of an altercation with a staffer.