Senator Hanson-Young has lodged a complaint with the Australian Federal Police about the message involving a firearm and vile name calling from a "supporter" of the Queensland politician.

Mr Christensen, by his actions, has given others permission to emulate his behaviour, after he used Facebook on Saturday to share a photo of himself pointing a gun alongside the comment: "You gotta ask yourself, do you feel lucky, greenie punks?".

The Greens senator has used Twitter to share a threat she says she received on Sunday night.

The subject line read "Bullets" with the sender expressing a hope "that George has one left in the chamber" in order to shoot her.

"It was a threat towards me; it was a pretty sexist one and a threat to shoot me," Senator Hanson-Young told ABC television on Monday.

"George Christensen is the thug here. And he should take responsibility for the actions that he has given license to."

Senator Hanson-Young says the federal government must condemn his actions and the Nationals should sack him.

"Are they really standards that you are willing, as prime minister, to walk by?" she asked of Prime Minister Malcolm Turnbull.

"If the leader of the National party, Barnaby Joyce, had any class he would sack him."

Mr Christensen later amended his post to read "You gotta ask yourself, do you have a sense of humour, greenie punks? Obviously not" before it was deleted.

Mr Turnbull described the post as "very inappropriate".

"I think we agree on that and he's taken it down," he told 3AW radio.

Federal Greens leader Richard Di Natale and an environmental activist have both referred Mr Christensen's post to federal police.

Labor called on Mr Christensen to apologise.

Mr Christensen is expected to hold a press conference later on Monday.

Australian Associated Press