Pyne accuses Greens of knifing Milne

Senior Liberal Christopher Pyne says the Australian Greens can no longer claim the moral high ground after "knifing" former leader Christine Milne.

"They put their forebears in Che Guevara and Fidel Castro to shame today because this was a revolution that took less than an hour," the education minister told Sky News.

Mr Pyne compared the Greens to the Democrats, who he said started "looking sick" to the Australian public once they began "knifing" their leaders.

He qualified his claims by saying discontent had been bubbling within the minor party for some time, leading to Wednesday's "cold-blooded" and "ruthless" leadership change to Richard Di Natale.

"They like to lecture Labor and the Liberals about bad politics versus this lovely perfect politics the Greens would give.

"But what we've seen today is they're just the same as any other political party."