Former Prime Minister Sir John Key is urging National to "take some responsibility" after the party's president accused the media of bias and "clickbait".
In a speech at National's AGM in Wellington on Saturday, president Peter Goodfellow criticised Prime Minister Jacinda Ardern, Labour and the media, describing the Government's daily coronavirus updates as "televangelistic".
"It was suddenly a crime for us to ask legitimate questions or comments, and daily broadcasts became televangelistic, like gospel to the masses.
"Democracy for a period of time gave way to a form of temporary tyranny," he said.
Sir John, a former National Party leader, said unity within the party would have prevented negative media reports leading up to the election.
Instead, the election campaign was marred by reports of National MPs leaking against party leader Judith Collins.
"My point would really be, we have a chance to control what the media say about us and if we have unity, and we're on message and we start talking about the things we want to do, eventually all the other stories drown out," Sir John told The AM Show on Monday.
"It's no different from a sporting team - if they don't eventually say, 'yep, the other guys played well' - but actually look in the mirror and say, 'we did these things wrong'.
"Take responsibility - we're the party of personal responsibility - that would be a great step forward to winning in '23."
Sir John believes Ardern is beatable and told the National AGM the party's MPs had to stop leaking as they were before the election.
"I was in a unique position to deliver that message - there's some validity in that this was a really difficult election to win - [but] if we want to win we actually have to win back those voters," Sir John said.
"We have to get voters who voted for us only three years ago to say - 'they're on the right message, they're thinking about me, they've got better policies, they're exposing the weaknesses of the Government'.
"Unless you start doing that and get control of that agenda, you can't win because you've got to win those votes, you can't just hope they'll come back to you."
Goodfellow, meanwhile, was re-elected as National Party president at the AGM on Saturday.
"We have a big job ahead of us and I'm confident our board has the skills and talent to deliver a strong and united Opposition," he said.