Scott Morrison says "keyboard warriors in their mother's basement" are responsible for online comments attacking his Christian faith.
The prime minister likened them to the people drawing swastikas on Jewish candidates' election signs, which he said had happened to Treasurer Josh Frydenberg and Julian Leeser.
It came after an anti-Adani coal mine protester compared working for the coal mine to working in Nazi Germany's gas chambers.
"Go and look on their social media contributions, you see a fair bit of that," Mr Morrison told reporters in Melbourne on Monday.
"There was another one, on another group, who was likening my praise in my own church on the weekend to some sort of Hitler salute. I mean, it's disgusting.
"These grubs are gutless and they're keyboard warriors in their mother's basement trying to make heroes of themselves. But the great Australian people are much bigger than them."
Mr Morrison was pictured worshipping at his Horizon Church in Sydney on Easter Sunday, attracting criticism and mockery online.
Regarding the gas chambers comment, anti-Adani protest organiser and former Greens leader Bob Brown said in a statement on Monday "I absolutely repudiate offensive comments such as those headlined in today's Murdoch press".
The WA branch of the CFMEU on Sunday posted a picture of Mr Morrison with his hand in the air, with the line "beware of false prophets (or should that be profits?)".
The tweet was later removed.
Australian Associated Press