Internet Pary leader Laila Harre believes the right's vilification of Kim Dotcom, and the left's failure to counter it, cost David Cunliffe the election.
She also said the party should have recognised the effectiveness of the right's portrayal of Mr Dotcom as electoral poison, and pulled him from the campaign's frontline.
Last night's election result delivered to Internet-Mana a lowly 1.26 per cent of the party vote - but it has failed to gain a foothold in Parliament because Mana leader Hone Harawira lost his grip on Te Tai Tokerau.
The result puts the future of the internet Party - and its alliance with Mana - in doubt.
This morning Ms Harre said that the campaign against Kim Dotcom fatally wounded the overall chances of changing the Government.
"Labour in particular, but also the Greens and NZ First, had the opportunity to accept the reality of Internet-Mana and build a narrative around a diverse, progressive alternative to National, or to effectively capitulate to National's narrative.
"In the end, we were used by the right to damage the left overall. The only way the left could have avoided that was to provide a counter-narrative, and they failed to do that, and that cost David Cunliffe the Prime Ministership."
Ms Harre said the party underestimated the public response to National's narrative.
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"We should have much more proactively withdrawn him from the campaign at an earlier point. In retrospect, we could have been much more vigorous in assessing that. But we also had to weigh up the risk that if we distanced him, that would have become a media story in itself. We were damned if we did, damned if we didn't.
"We were never able to move the Internet-Mana identity beyond the Kim-Dotcom identity. You only have to look at the news coverage from day one on anything that Kim said or did.
"This isn't about blaming the media. But the media chose only to cover, even when it was side-show material, events around Kim. There was almost no coverage of internet-Mana's initiatives."
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She said she was yet to speak with Mr Harawira, but she was devastated for him.
Mr Harawira has declined to comment today, but is reportedly refusing concede until the special votes have been counted.
"We anticipate he would narrow the gap on the specials, but the election night result is pretty decisive," Ms Harre said.