The Greens have issued an urgent appeal to party supporters for donations to set up a "fighting fund" amid an increasingly bitter row with the Labor Party.

At the weekend, senior Labor figures launched a concerted campaign to differentiate the ALP from the Greens, the party it relies on to stay in government.

They called the Greens "dangerous", "loopy" and a "threat to democracy".

New South Wales Labor boss Sam Dastyari wants to end to automatic preferencing of the Greens at the next federal election.

It has sparked a public feud between the two parties, something Greens leader Christine Milne has described as an "all-out attack" on the 1.6 million people who vote Green.

Greens supporters are being asked to "chip in" $25, $40 or $100 to fund newspaper advertisements aimed at countering the campaign.

"With our shared values under fire in every newspaper, there is something you can do to stand up for everything we've achieved together," Senator Milne writes in an email to party supporters.

The public attack on the Greens has made some in Labor uneasy, with some describing it as "clumsy".

Labor senator Doug Cameron has publicly lambasted the Greens for their "immature" approach to some policy debates, but he says he is concerned the recent attacks are designed to move the ALP "further to the right".

"I've got problems with the Greens in relation to how they've behaved over refugees and on carbon price... (but) I didn't want that to be used as some excuse to say that the (Labor) party should not have progressive left policies," Senator Cameron told PM.

Senator Cameron says he has raised his concerns directly with Mr Dastyari today and received an assurance the debate around preference flows to the Greens was not designed to "drag" the party to the right.

"In relation to putting the Greens last... I understand there is some discussion going on about an appropriate resolution (at this weekend's NSW ALP state conference)," Senator Cameron said.

No coincidence

Senator Milne says it is no coincidence that Labor has ramped up its attacks on the Greens in the days leading up to the by-election in the Victorian state seat of Melbourne.

"Greens candidate Dr Cathy Oke was on track to win the seat next week, but the attacks have come thick and fast on her as part of the national ALP campaign," Senator Milne said in the email.

"We want to publish an ad in Melbourne's Age newspaper so we can share our positive vision with voters before election day - and that's just the start."

Opposition Leader Tony Abbott yesterday described the brawl as a "civil war" within the Labor Party, arguing those in the ALP who were attacking the Greens were effectively attacking the Prime Minister, given her post-election agreement with the minor party.

"You can't attack the deal with the Greens without implicitly attacking the person who did the deal," he said.