The party has also blamed “big Labor” after candidate Alex Bhathal was trumped by former ACTU boss Ged Kearney on Saturday.
Asked if he would resign over the loss, Di Natale said “no”.
“We had a big Labor machine against us, corporate money, the significant support of the union movement – it was always going to be tough,” he told ABC radio today.
“It’s very difficult to run a campaign when you’re not just fighting a machine like that but you’re also fighting some of your own people.”
Bhathal’s campaign for the inner-Melbourne seat was rattled by media reports of internal party complaints against her lodged by a number of Greens branch members.
Another internal review is underway into how the leak occurred.
“Those people who are found to be responsible for leaking and undermining our candidate need to be expelled,” Di Natale said.
Deputy Greens leader Adam Bandt faced questions about the matter while campaigning in Batman.
“The infighting played a big role,” he told ABC radio.
“I don’t think people like political parties doing that sort of stuff generally, certainly not doing it during an election campaign.”
“People would like us to conduct ourselves in a respectful manner and probably have those debates internally.”
This was Bhathal’s sixth run for Batman, and Bandt “took his hat off” to her for turning it into a marginal seat, saying he would back her if she wanted to run again.
“She’s been through a pretty bruising experience and had a lot of stuff put out about her,” he said.
Bhathal withdrew from social media after her defeat, apparently deleting her Facebook and Twitter accounts on Monday.
The Liberal party did not run a candidate in the by-election, which was called after sitting Labor MP David Feeney resigned over his dual-citizenship.
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