Just how much has the Jami-Lee Ross saga damaged the National Party?

The National Party has taken a substantial hit to its previously stable reputation in the last seven days.

Unanswered questions over donation handling, comments perceived by some as racist and harassment claims were all part of the week from hell which was ignited by rogue MP Jami-Lee Ross.

He released secretly-recorded audio which reflected badly on Simon Bridges and even made a formal police complaint accusing him of electoral fraud.

Political commentator David Farrar says it's undeniable the saga has hurt National.

"I don't think anyone could say a party that's gone through the last week or two isn't damaged."

He told RadioLIVE that inter-party squabbling will prove just as unpopular with Kiwi voters as the lack of action taken on Mr Ross' alleged harassment and bullying.

"The public don't like parties that are focused on themselves and their internal issues. They want to hear the politicians talking about what matters to four and a half million New Zealanders - their policy on education, schools, on the economy, on jobs.

"I have no doubt this has damaged National quite significantly, but the more important question is for how long?"

It's been a week since Mr Ross launched his attack on Simon Bridges and the National Party, which began with a pre-emptive Twitter strike just before Mr Bridges announced an inquiry had found he was the likely leaker.

Mr Farrar says National needs to pull itself together after the tumultuous events of the last seven days.

"If they can get through this and get to a resolution, then they've got an opportunity to repair the damage. I'm a pollster and one of the things I've noticed in the polls is if you drop 10 percent in two weeks, you can actually regain that 10 percent back in another few weeks.

"What's really damaging to a party is when you drop just half a percent a week for week after week after week. That gradual decline is much harder to reverse than a shock fall due to some event, because you can actually recover from that."

He says National will want to put the entire issue behind them before the Christmas break.

"Whether it resolves with a by-election or whether it escalates or whether there's some sort of understanding, I think the key for them will be if they can start 2019 focusing on what matters to New Zealanders rather than this situation."

As for Mr Bridges, he doesn't think he's a dead leader walking.

"In the short term this has ironically backfired, it's totally united the caucus behind him."

However he says that could change closer to election time. 

"National's like any other party. If you get to a point at which your hopes at the election look better under a different leader, then the caucus will make a decision that it's maybe time for a change."

Mr Farrar says with the sad news that Mr Ross has been taken to a mental health care facility, it's time for National to "take a breather".

"They were locked in a constant escalation... every day, twice a day in the last week, the pressure was going up and up. National was probably looking at whether they would use the waka-jumping legislation to remove him from Parliament.

"My assumption is nobody's going to be rushing to any decisions on that now he's having some treatment. Let's just pause now and see where things get to."

He also hopes the media will take a step back from the story to allow everyone involved to heal.

"It doesn't mean there's going to be a happy ending for everyone. There's still some very serious issues and whether they can be resolved is not at all clear. At best there's an opportunity for a bit of calming down and reflection."

His advice for Mr Ross is to focus on his own wellbeing, "rather than utu on those he considers have wronged him".