Sir John Key says the National Party needs to "look in the mirror" instead of blaming the media or anyone else for its woeful election result.
His comments follow Peter Goodfellow's speech at National's AGM yesterday, when the party president railed against what he saw as "clickbait" and biased media.
Goodfellow also described Prime Minister Jacinda Ardern as a "celebrity" leader, her Covid-19 response as "temporary tyranny", and her regular Covid-19 updates as "tele-vangelical" addresses to the nation.
Last night, the party board voted for Goodfellow, the party's longest-serving president, to continue in the role.
This morning, Key told Newstalk ZB it was up to the party's leadership team to critique Goodfellow's speech, if they wished.
But he added: "If we blame the media or go and blame other people, we're going to forget to actually look in the mirror and we have to take responsibility.
"If we don't learn from it, we'll just repeat those mistakes and we won't move on. The reality is, you probably learn more from your mistakes than you do from your victories. If the All Blacks don't go and watch a few tapes of their game in recent time, they'll repeat their mistakes."
Key acknowledged that the Covid-19 pandemic gave the Government an "unprecedented" platform to communicate to the country.
"But we have to take responsibility for our own actions. We failed in a series of different ways, from leadership changes to leaking to disunity. All of those get punished very strongly by an electorate.
"If we want to be silly enough to continue with the sorts of games that have been played recently, then they [media] are going to report them and we've only got ourselves to blame."
Despite that, he backed Goodfellow in the president's role, saying he had done "a tremendous job" in fund-raising for the party.
"He's a very effective president, in my view."
Party leader Judith Collins, when asked about Goodfellow's speech yesterday, said: "I think the president did an excellent speech – it's one where he, I think, contributed very well to the party's AGM."
Key also backed Collins, saying she was an extremely hard worker who became leader in trying circumstances.
"I don't think it would have mattered too much who became leader of the National Party 16 weeks out from the election.
"It was a very difficult position. It's unlikely anyone would have picked up the reins and would have won at that time."
He said the party had to win back the 413,800-odd voters it had lost since 2017 by differentiating itself from the Government, and convincing voters it not only had a good plan, but could execute it.
"There's an awful lot of New Zealanders who maybe don't want the Government and don't want billions of dollars being borrowed and don't want extra taxes and regulations."
But he had a warning for National.
"You can underestimate Jacinda Ardern but you do so at your own peril. She'll communicate strongly. They have all of the levers of Government. They aren't shy about spending money and throwing it at some of those first-time Labour voters.
"They're not going to be an easy Government to knock off its perch."