Labor and the Greens have ridiculed attempts by one of Tony Abbott's backbenchers to have the RSPCA stripped of its "royal" title.

Victorian Nationals senator Bridget McKenzie plans to write to the Queen requesting the change, over concerns the group has been engaging in too much activist work, like animal rights group People for the Ethical Treatment of Animals (PETA).

"They're trading on their status, given to them, bestowed onto them, by the royal family," Senator McKenzie said.

"Our Queen is a race horse owner, she's a hunter, she's a shooter and she's also a farmer and more importantly she's actually the patron of animal welfare in Britain, so those concepts aren't mutually exclusive for the Queen.

"In the world that the RSPCA wants to create, I mean, [the movie] Babe would never have occurred.

"Imagine a world without Babe."

The RSPCA — which stands for the Royal Society for the Prevention of Cruelty to Animals — said the debate was very odd and Senator McKenzie's push was yet to be endorsed by any of her federal Coalition colleagues.

"She clearly has delusions of grandeur," Labor's Agriculture spokesman Joel Fitzgibbon said.

"A National Party senator gets to write to the Queen — good luck with a response. This puts Australia in a very bad light. This is a charity that has existed for 150 years."

Greens spokeswoman Lee Rhiannon was just as scathing.

"[This] is about trying to downgrade the standing this organisation has and undermine its important work," she said.

It is highly unlikely the Queen would interfere in the running of the Australian organisation.

But Senator McKenzie said the RSPCA had strayed from its core duties by taking a more active role in campaigns to end live exports and hunting.

"The RSPCA's denigration and maligning of hunters and shooters and families and children that participate in this is uncalled for," she told Radio National.

"It's not the core business, it's not why it was set up and I believe our monarch would have a problem with that."

Not a particularly good use of time: RSPCA

The senator's decision to write to the Queen follows growing debate in the farming sector about the RSPCA's role as an advocate and enforcement agency.

"Now they have gone down that animal activist track and it's disappointing a lot of people basically," Victorian Farmer's Federation president Peter Tuohey said.

But the RSPCA rejects the criticism.

"I am interested in the way that Bridget chooses to use her time — I don't think it's a particularly good use of time," RSPCA chief executive Liz Walker said.

"We know that the community expects us to be there to look after animals and improve their lot, [and] that's what we intend to do."

The RSPCA said the royal title did not afford it any special powers.

"She's going to write to the Queen for what? For a name change," Mr Fitzgibbon said.

"It's a distraction."